
TY  - JOUR
TI  - Inhibition of superoxide anion generation by YC-1 in rat neutrophils through cyclic GMP-dependent and -independent mechanisms.
N2  - 3-(5'-Hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1), a soluble guanylyl cyclase (sGC) activator, inhibited formyl-methionyl-leucyl-phenylalanine (fMLP)-induced superoxide anion (O(2)*(-)) generation and O(2) consumption in rat neutrophils (IC(50) values of 12.7+/-3.1 and 17.7+/-6.9 microM, respectively). Inhibition of O(2)*(-) generation by YC-1 was partially reversed by the cyclic GMP-lowering agent 6-anilinoquinoline-5,8-quinone (LY83583) and by the Rp isomer of 8-(4-chlorophenylthio)guanosine-3',5'-monophosphorothioate (Rp-8-pCPT-cGMPS), a cyclic GMP-dependent protein kinase inhibitor. In cell-free systems, YC-1 failed to alter O(2)*(-) generation during dihydroxyfumaric acid autoxidation, phorbol 12-myristate 13-acetate (PMA)-activated neutrophil particulate NADPH oxidase preparation, and arachidonic acid-induced NADPH oxidase activation. YC-1 increased cellular cyclic GMP levels through the activation of sGC and the inhibition of cyclic GMP-hydrolyzing phosphodiesterase activity. The plateau phase, but not the initial spike, of fMLP-induced [Ca(2+)](i) changes was inhibited by YC-1 (IC(50) about 15 microM). fMLP- but not PMA-induced phospholipase D activation was inhibited by YC-1 (IC(50) about 28 microM). Membrane-associated ADP-ribosylation factor and Rho A in cell activation was also reduced by YC-1 at a similar concentration range. Neither cytosolic protein kinase C (PKC) activity nor PKC membrane translocation was altered by YC-1. YC-1 did not affect either fMLP-induced phosphatidylinositol 3-kinase activation or p38 mitogen-activated protein kinase phosphorylation, but slightly attenuated the phosphorylation of extracellular signal-regulated kinase. Collectively, these results indicate that the inhibition of the fMLP-induced respiratory burst by YC-1 is mediated by cyclic GMP-dependent and -independent signaling mechanisms.
AD  - Department of Education and Research, Taichung Veterans General Hospital, 160 Chung Kang Road, Sec. 3, 407, ROC, Taichung, Taiwan. w1994@vghtc.gov.tw
AU  - Wang,J.P.
AU  - Chang,L.C.
AU  - Raung,S.L.
AU  - Hsu,M.F.
AU  - Huang,L.J.
AU  - Kuo,S.C.
PY  - 2002///Feb 15
JA  - Biochem Pharmacol
VL  - 63
IS  - 4
SP  - 577
EP  - 85
ER  - 

TY  - JOUR
TI  - Activation of soluble guanylate cyclase causes relaxation of corpus cavernosum tissue: synergism of nitric oxide and YC-1.
N2  - Nitric oxide (NO) activates corpus cavernosum smooth muscle soluble guanylate cyclase (sGC) and increases the synthesis of cGMP that results in smooth muscle relaxation and ultimately, penile erection. To characterize sGC and define the potential synergy between NO and the allosteric activator YC-1 in corpus cavernosum, rat sGC was activated by either sodium nitroprusside (SNP) or YC-1, and YC-1 potentiated the effects of SNP with a 200-fold activation of sGC. Both SNP and YC-1 decreased the Km and increased the Vmax. ODQ significantly inhibited sGC activated by SNP with IC50 of 0.5 nM, but did not affect the sGC activated by YC-1 as well as basal sGC activity. SNP and YC-1 synergistically increased intracellular cGMP levels in rabbit corpus cavernosum smooth muscle cell cultures. YC-1 significantly relaxed rabbit cavernosum tissue strips in organ baths with an EC50 of 8.4 microM. In the presence of L-nitroarginine methyl ester to block endogenous NO production, co-administration of SNP shifted the dose response of YC-1 to the left, showing the synergism of SNP and YC-1 in tissue strips. In view of the clinical efficacy of phosphodiesterase-5 inhibitors, activation of sGC may provide an alternative means for enhancing the activity of neurally derived NO during sexual stimulation in the corpus cavernosum, representing a novel approach for the treatment of erectile dysfunction.
AD  - Neuroscience, Global Pharmaceutical Research, Abbott Laboratories, Abbott Park, Illinois 60064-6119, USA. masaki.nakane@abbott.com
AU  - Nakane,M.
AU  - Hsieh,G.
AU  - Miller,L.N.
AU  - Chang,R.
AU  - Terranova,M.A.
AU  - Moreland,R.B.
AU  - Kolasa,T.
AU  - Brioni,J.D.
PY  - 2002///Apr
JA  - Int J Impot Res
VL  - 14
IS  - 2
SP  - 121
EP  - 7
ER  - 

TY  - JOUR
TI  - Inhibition of deactivation of NO sensitive guanylyl cyclase accounts for the sensitizing effect of YC-1.
N2  - Many of the physiological effects of the signaling molecule nitric oxide are mediated by the stimulation of the NO-sensitive guanylyl cyclase. Activation of the enzyme is achieved by binding of NO to the prosthetic heme group of the enzyme and the initiation of conformational changes. So far, the rate of NO dissociation of the purified enzyme has only been determined spectrophotometrically, whereas the respective deactivation, i.e. the decline in enzymatic activity, has only been determined in cytosolic fractions and intact cells. Here, we report on the deactivation of purified NO-sensitive guanylyl cyclase determined after addition of the NO scavenger oxyhemoglobin or dilution. The deactivation rate corresponded to a half life of the NO/guanylyl cyclase complex of approximately 4 seconds which is in good accordance with the spectrophotometrically measured NO dissociation rate of the enzyme. The deactivation rate of the enzyme determined in platelets yielded a much shorter half life indicating either partial damage of the enzyme during the purification procedure or the existence of endogenous deactivation accelerating factors. YC-1, a component causing sensitization of guanylyl cyclase towards NO, inhibited deactivation of GC, resulting in a tremendously prolonged half life of the NO/guanylyl cyclase complex of more than 10 min. The deactivation of an ATP-utilizing guanylyl cyclase mutant was almost unaffected by YC-1, indicating the existence of a special structure within the catalytic domain being required for YC-1 binding or for the transduction of the YC-1 effect. In contrast to the wild type enzyme, YC-1 did not increase NO-sensitivity of this mutant, clearly establishing inhibition of deactivation as the underlying mechanism of the NO-sensitizer YC-1.
AD  - Pharmakologie und Toxikologie, Ruhr-Universitat Bochum, Bochum 44780.
AU  - Russwurm,M.
AU  - Mergia,E.
AU  - Mullershausen,F.
AU  - Koesling,D.
PY  - 2002///Apr 26
JA  - J Biol Chem
VL  - 277
IS  - 28
SP  - 24883
EP  - 8
ER  - 

TY  - JOUR
TI  - Pharmacology of the nitric oxide receptor, soluble guanylyl cyclase, in cerebellar cells.
N2  - The nitric oxide (NO) receptor, soluble guanylyl cyclase (sGC), is commonly manipulated pharmacologically in two ways. Inhibition of activity is achieved using 1-H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-l-one (ODQ) which oxidizes the haem prosthetic group to which NO binds, while the compound 3-(5-hydroxymethyl-2-furyl)-1-benzylindazole (YC-1) is considered an 'allosteric' activator. Knowledge of how these agents function and interact in a normal cellular environment is limited. These issues were addressed using rat cerebellar cells. Inhibition by ODQ was not simply competitive with NO. The rate of onset was ODQ concentration-dependent and developed in two kinetic phases. Recovery from inhibition occurred with a half-time of approximately 5 min. YC-1 slowed the rate at which sGC deactivated on removal of NO by 45 fold, consistent with YC-1 increasing the potency of NO for sGC. YC-1 also enhanced the maximal response to NO by 2 fold. Furthermore, when added to cells in which sGC was 90% desensitized, YC-1 abruptly enhanced sGC activity to a degree that indicated partial reversal of desensitization. After pre-exposure to YC-1, sGC became resistant to inhibition by ODQ. In addition, YC-1 rapidly reversed inhibition by ODQ in cells and for purified sGC, suggesting that YC-1 either increases the NO affinity of the oxidized sGC haem or reverses haem oxidation. It is concluded that the actions of ODQ and YC-1 on sGC are broadly similar in cells and purified preparations. Additionally, YC-1 transiently reverses sGC desensitization in cells. It is hypothesized that YC-1 has multiple actions on sGC, and thereby both modifies the NO binding site and enhances agonist efficacy.
AD  - Wolfson Institute for Biomedical Research, University College London, Gower St., London WC1E 6AU, U.K. Current address: Division of Neurophysiology, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA.
AU  - Bellamy,T.C.
AU  - Garthwaite,J.
UR  - http://www.brjpharmacol.org/cgi/content/full/136/1/95
PY  - 2002///May
JA  - Br J Pharmacol
VL  - 136
IS  - 1
SP  - 95
EP  - 103
ER  - 

TY  - JOUR
TI  - Nitric oxide independent activation of guanylate cyclase by YC-1 causes erectile responses in the rat.
N2  - PURPOSE: Activation of soluble guanylate cyclase with a subsequent increase in intracellular levels of cyclic guanosine monophosphate is necessary for normal erection. In vascular tissue 3(5'-hydroxymethyl-2'-furyl-1-benzyl indazole (YC-1) (Abbott Laboratories, North Chicago, Illinois) has been shown to stimulate soluble guanylate cyclase independent of nitric oxide. We studied whether YC-1 modulates erectile responses in the rat. MATERIALS AND METHODS: The effects of YC-1 given intracavernously or intraperitoneally on intracavernous pressure were investigated in rats. Functional effects of YC-1 on neuronal and endothelial nitric oxide relaxations were studied in 3 x 10(-6) M. 1-noradrenaline contracted preparations of rat isolated corpus cavernosum. RESULTS: Intracavernous YC-1 (10 micromol. kg.-1) produced erectile responses with a mean intracavernous pressure plus or minus standard error of mean of 81 +/- 17 cm. water (p &lt;0.001) and a mean duration of 7.1 +/- 3.3 minutes (p &lt;0.001). YC-1 (10 micromol. kg.-1) given intraperitoneally also increased the amplitude and duration of erectile responses to cavernous nerve stimulation. Mean peak intracavernous pressure increased from 63 +/- 6 to 10(2) +/- 16 cm. water (p &lt;0.05). Erections induced by a submaximal dose of 25 microg. kg.-1 apomorphine s.c. increased in number after 10 micromol. kg.-1 YC-1 intraperitoneally (p &lt;0.05). In vitro nerve induced relaxant responses were enhanced by increasing concentrations of YC-1. Relaxations at 20 Hz. were increased from a mean of 9% +/- 5% to 52% +/- 5% at a YC-1 concentration of 10(-5) M. (p &lt;0.001). At this concentration carbachol induced relaxations were enhanced from a mean of 19% +/- 3% to 40% +/- 9% (p &lt;0.05). CONCLUSIONS: YC-1 can evoke erectile responses when given intracavernously and it enhances erections induced by cavernous nerve stimulation and apomorphine when given systemically. In vitro YC-1 enhances electrically evoked relaxations in rat corpus cavernosum. YC-1 represents an interesting pharmacological principle that may be useful for treating erectile dysfunction.
AD  - Department of Clinical Pharmacology, University of Lund, Sweden.
AU  - Mizusawa,H.
AU  - Hedlund,P.
AU  - Brioni,J.D.
AU  - Sullivan,J.P.
AU  - Andersson,K.E.
KW  - 0 (Enzyme Activators)
KW  - 0 (Indazoles)
KW  - 10102-43-9 (Nitric Oxide)
KW  - 154453-18-6 (3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole)
KW  - 58-00-4 (Apomorphine)
KW  - EC 4.6.1.2 (Guanylate Cyclase)
KW  - Animal
KW  - Apomorphine [pharmacology]
KW  - Comparative Study
KW  - Dose-Response Relationship, Drug
KW  - Enzyme Activators [pharmacology]
KW  - Guanylate Cyclase [metabolism]
KW  - Hydrostatic Pressure
KW  - Indazoles [pharmacology]
KW  - Injections
KW  - Injections, Intraperitoneal
KW  - Male
KW  - Nitric Oxide [physiology]
KW  - Penile Erection [drug effects]
KW  - Penile Erection [physiology]
KW  - Penis [drug effects]
KW  - Rats
PY  - 2002///May
JA  - J Urol
VL  - 167
IS  - 5
SP  - 2276
EP  - 81
ER  - 

TY  - JOUR
TI  - Isoforms of NO-sensitive guanylyl cyclase.
N2  - By the formation of cGMP the NO-sensitive guanylyl cyclase plays a key role within the NO/cGMP signaling cascade involved in vascular regulation and neurotransmission. The prosthetic heme group of the enzyme acts as the NO sensor, and binding of NO induces conformational changes leading to an up to 200-fold activation of the enzyme. The unexpected fast dissociation half-life of NO of a few seconds is fast enough to account for the deactivation of the enzyme in biological systems. YC-1 and its analogues acting as NO sensitizers uncovered a new pharmacologically and conceivably physiologically relevant regulatory principle of the enzyme. Two existing isoforms of the heterodimeric guanylyl cyclase (alpha1beta1, alpha2beta1) are known that are functionally indistinguishable. Up to now, the NO-sensitive guanylyl cyclase has been considered as a soluble enzyme. However, recent evidence about the alpha2beta1 isoform interacting with a PDZ domain of the postsynaptic scaffold protein PSD-95 suggests that the alpha2 subunit directs a membrane association of this isoform. The interaction with PSD-95 locates the alpha2beta1 isoform in close proximity to the NO-generating NO synthase thereby enabling the NO sensor to respond to locally raised NO concentrations.
AD  - Pharmakologie und Toxikologie, Medizinische Fakultat MA N1, Ruhr-Universitat Bochum, Germany. koesling@iname.com
AU  - Russwurm,M.
AU  - Koesling,D.
PY  - 2002///Jan
JA  - Mol Cell Biochem
VL  - 230
IS  - 1-2
SP  - 159
EP  - 64
ER  - 

TY  - JOUR
TI  - BAY 41-2272 activates two isoforms of nitric oxide-sensitive guanylyl cyclase.
N2  - Soluble guanylyl cyclase is an important target for endogenous nitric oxide and the guanylyl cyclase modulator, YC-1. Recently BAY 41-2272 was identified as a similar but more potent and more specific substance. While YC-1 also acts as non-specific phosphodiesterase inhibitor, BAY 41-2272 is devoid of an effect on phosphodiesterases. BAY 41-2272 has so far only been tested on the alpha(1)/beta(1) heterodimeric isoform of soluble guanylyl cyclase and its binding site has been mapped to a region in the alpha(1) subunit amino-terminal sequence. Although this region is poorly conserved in the alpha(2) subunit, we show in the current study that the alpha(2)/beta(1) heterodimeric enzyme isoform is activated by BAY 41-2272. Deletion analysis of the alpha(2) subunit and co-expression with the beta(1) subunit in the baculovirus/Sf9 system is consistent with the amino-terminal amino acids 104 to 401 of the alpha(2) subunit as binding site for BAY 41-2272.
AD  - Institut fur Experimentelle und Klinische Pharmakologie, Universitat Hamburg, Martinistrasse 52, Hamburg, D-20246, Germany.
AU  - Koglin,M.
AU  - Stasch,J.P.
AU  - Behrends,S.
KW  - 0 (BAY 41-2272)
KW  - 0 (Enzyme Activators)
KW  - 0 (Hydrazines)
KW  - 0 (Indazoles)
KW  - 0 (Isoenzymes)
KW  - 0 (Nitric Oxide Donors)
KW  - 0 (Protein Subunits)
KW  - 0 (Pyrazoles)
KW  - 0 (Pyridines)
KW  - 0 (Receptors, Cytoplasmic and Nuclear)
KW  - 0 (nitric oxide receptor)
KW  - 10102-43-9 (Nitric Oxide)
KW  - 154453-18-6 (3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole)
KW  - 86831-65-4 (1,1-diethyl-2-hydroxy-2-nitrosohydrazine)
KW  - Animal
KW  - Binding Sites [physiology]
KW  - Cell Line
KW  - Dose-Response Relationship, Drug
KW  - Enzyme Activation [drug effects]
KW  - Enzyme Activators [pharmacology]
KW  - Human
KW  - Hydrazines [pharmacology]
KW  - Indazoles [pharmacology]
KW  - Isoenzymes [drug effects]
KW  - Isoenzymes [genetics]
KW  - Isoenzymes [metabolism]
KW  - Mutagenesis, Site-Directed
KW  - Nitric Oxide [pharmacology]
KW  - Nitric Oxide Donors [pharmacology]
KW  - Protein Subunits
KW  - Pyrazoles [pharmacology]
KW  - Pyridines [pharmacology]
KW  - Rats
KW  - Receptors, Cytoplasmic and Nuclear [drug effects]
KW  - Receptors, Cytoplasmic and Nuclear [genetics]
KW  - Receptors, Cytoplasmic and Nuclear [metabolism]
KW  - Spodoptera
PY  - 2002///Apr 12
JA  - Biochem Biophys Res Commun
VL  - 292
IS  - 4
SP  - 1057
EP  - 62
ER  - 

TY  - JOUR
TI  - Insulin increases NADH/NAD+ redox state, which stimulates guanylate cyclase in vascular smooth muscle.
N2  - BACKGROUND: Insulin inhibits contraction and migration of primary confluent, cultured canine vascular smooth muscle cells (VSMCs) with inducible nitric oxide synthase (iNOS) by stimulating cyclic GMP (cGMP) production. The present study was performed to determine how insulin stimulates guanylate cyclase activity in these cells. METHODS: Primary cultured VSMC were obtained from canine femoral arteries. Lactate and pyruvate levels were measured by enzymatic assays, cGMP production by radioimmunoassay, iNOS activity by conversion of arginine to citrulline, and cell contraction by photomicroscopy. RESULTS: Insulin (1 nmol/L) increased cGMP production fivefold in VSMC with iNOS while raising the lactate-to-pyruvate ratio (LPR) from 3.1 +/- 0.5 to 10.0 +/- 1.6 (P &lt; .05), indicating a rise in the ratio of reduced/oxidized nicotinamide adenine dinucleotide (NADH/NAD+) redox state of the cell. Insulin's stimulation of cGMP production was blocked by 0.1 mmol/L NG-monomethyl-L-arginine (L-NMMA) indicating dependence on iNOS activity, but insulin did not affect iNOS activity. Blocking insulin's increase in LPR by pyruvate (0.5 mmol/L) or oxaloacetate (0.5 mmol/L) completely inhibited the insulin-stimulated component of cGMP production. Pyruvate also blocked insulin's inhibition of serotonin-induced contraction in nonproliferated cells. In the absence of insulin, 5 mmol/L lactate or isocitrate increased the LPR by 420% +/- 47% and 167% +/- 20%, respectively (both P &lt; .05), and stimulated cGMP production by 1,045% +/- 272% and 278% +/- 33%, respectively (both P &lt; .05) by an L-NMMA-inhibitable mechanism. Although cGMP production in cells with iNOS was increased by insulin, the stimulation of cGMP production in cells without iNOS by 3-(5'-hydroxymethyl-2'furyl)-1-benzyl indazole (YC-1) was not affected by insulin, suggesting that insulin does not stimulate guanylate cyclase activity directly. CONCLUSION: We conclude that insulin increases cGMP production in VSMC with iNOS by raising the cell NADH/NAD+ redox state, which may increase the availability of iNOS-derived NO.
AD  - Department of Medicine. The University of Texas Health Science Center, Houston 77225, USA.
AU  - Kahn,A.M.
AU  - Allen,J.C.
AU  - Zhang,S.
PY  - 2002///Mar
JA  - Am J Hypertens
VL  - 15
IS  - 3
SP  - 273
EP  - 9
ER  - 

TY  - JOUR
TI  - Carbon monoxide relaxes the female pig urethra as effectively as nitric oxide in the presence of YC-1.
N2  - PURPOSE: Nitric oxide (NO) and carbon monoxide (CO) have been suggested to relax smooth muscle by activating soluble guanylate cyclase (sGC), binding to the same site of the enzyme. 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1) (Cayman Co., Malmo, Sweden) increases the catalytic rate of sGC by binding to an allosteric site. We investigated whether YC-1 can modulate the relaxant responses of isolated urethral smooth muscle to exogenous CO, (NO) and electrical field stimulation. MATERIALS AND METHODS: In spontaneously active and noradrenaline (Sigma-Aldrich Chemie GmbH, Steinheim, Germany) pre-contracted preparations of circular urethral smooth muscle from female pigs relaxant responses were evoked by electrical field stimulation before and after incubation with 10(-5) M. YC-1. The concentration-response curves for CO and NO were investigated in noradrenaline pre-contracted strips before and after incubation with YC-1. The tissue contents of cyclic 3',5'-guanosine monophosphate (cGMP) and cyclic adenosine monophosphate after electrical field stimulation, and the administration of CO or NO was investigated in the absence and presence of YC-1. RESULTS: YC-1 significantly increased the amplitude of the relaxations evoked by electrical field stimulation, CO and NO, and simultaneously caused significant increases in the cGMP content in all preparations. The effect on CO induced relaxant responses was conspicuous. In the presence of YC-1 the potency and maximal relaxant effect of CO were similar to those of NO in the absence of YC-1. CONCLUSIONS: YC-1 enhances cGMP dependent relaxant responses of the female pig urethra in vitro. The finding that the response to CO was greatly increased after sensitizing sGC suggests a potential for CO as a relaxant mediator in urethral smooth muscle.
AD  - Department of Clinical Pharmacology, Lund University Hospital, Lund, Sweden.
AU  - Schroder,A.
AU  - Hedlund,P.
AU  - Andersson,K.E.
PY  - 2002///Apr
JA  - J Urol
VL  - 167
IS  - 4
SP  - 1892
EP  - 6
ER  - 

TY  - JOUR
TI  - Activators of soluble guanylate cyclase for the treatment of male erectile dysfunction.
N2  - Soluble guanylate cyclase (sGC) is an important enzyme in corpus cavernosum smooth muscle cells as it is one of the regulators of the synthesis of cGMP. The efficacy of sildenafil (Viagratrade mark) in the treatment of male erectile dysfunction indicates the importance of the cGMP system in the erectile response as the increased levels of cGMP induce relaxation of the corpus cavernosum. sGC is physiologically activated by nitric oxide (NO) during sexual stimulation, and its activity can be pharmacologically enhanced by several NO-donors. Agents like YC-1 can also activate sGC after binding to a novel allosteric site in the enzyme, a site different from the NO binding site. YC-1 can relax rabbit cavernosal tissue and it facilitates penile erection in vivo. This review summarizes the enzymology, biochemistry and pharmacology of this novel allosteric site and its relevance for the regulation of penile function. This type of sGC activators represent a new class of compounds with a different pharmacological profile in comparison to the classical NO-donors and they could be beneficial for the treatment of male erectile dysfunction. DOI: 10.1038/sj/ijir/3900801
AD  - Neuroscience Research, Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, Illinois, USA.
AU  - Brioni,J.D.
AU  - Nakane,M.
AU  - Hsieh,G.C.
AU  - Moreland,R.B.
AU  - Kolasa,T.
AU  - Sullivan,J.P.
PY  - 2002///Feb
JA  - Int J Impot Res
VL  - 14
IS  - 1
SP  - 8
EP  - 14
ER  - 


TY  - BOOK
ID  - smith1975metalloporphyrins
BT  - Porphyrins and metalloporphyrins
A1  - Smith,K.M.
Y1  - 1975///
KW  - Porphyrins
KW  - Metalloporphyrins
KW  - Spectrophotometry [methods]
KW  - spectroscopy
RP  - NOT IN FILE
CY  - Amsterdam
PB  - Elsevier Scientific Publishing Company
ER  - 

TY  - CHAP
ID  - Lewicki1995natriureticpeptidefamily
T1  - Physiological studies of the natriuretic peptide family
A1  - Lewicki,J.A.
A1  - Protter,A.A.
Y1  - 1995///
N1  - Atrial Natriuretic Peptide   Cardiac synthesis and secretion of ANP   Regulation of ANP Gene Expression   Regulation of ANP Release ANP Receptors   Biologic Actions of ANP Brain Natriuretic Peptide (BNP) BNP Structure   Biosynthesis of BNP   Biological Actions of BNP C-Type Natriuretic Peptide (CNP)   Biologic Actions of CNP Modulators of Natriuretic Peptide Clearance   Effects of Clearance Receptor Blockers Effects of Neutral Endopeptidase Inhibitors Role of the Natriuretic Peitedes in Physiology and Disease   Hypertension   Congestive Heart Failure   Supraventricular Tachyarrhythmias   Acute Renal Dysfunction
KW  - natriuretic
KW  - ANF
KW  - ANP
KW  - receptors
KW  - BNP
KW  - CNP
KW  - hypertension
KW  - congestive heart failure
KW  - review
KW  - cardiac
KW  - regulation
KW  - gene expression
KW  - expression
KW  - brain
KW  - structure
KW  - biosynthesis
KW  - receptor
KW  - inhibitor
KW  - physiology
KW  - renal
KW  - study
KW  - Peptides
KW  - atrial natriuretic peptide
KW  - MODULATOR
KW  - secretion
KW  - Gene Expression Regulation
RP  - IN FILE
SP  - 1029
EP  - 1053
VL  - 2
T2  - Hypertension: Pathophysiology, Diagnosis, and Management
A2  - Laragh,J.H.
A2  - Brenner,B.M.
IS  - 61
CY  - New York
PB  - Raven Press, Ltd.
ER  - 

TY  - JOUR
TI  - Nitric oxide activation of soluble guanylyl cyclase reveals high and low affinity sites that mediate allosteric inhibition by calcium.
N2  - Cyclic GMP (cGMP) and Ca(2+) regulate opposing mechanisms in (patho)physiological processes reflected in the reciprocal regulation of their intracellular concentrations. Although mechanisms by which cGMP regulates [Ca(2+)](i) have been described, those by which Ca(2+) regulates [cGMP](i) are less well understood. In the present study, Ca(2+) inhibited purified sGC activated by sodium nitroprusside (SNP), a precursor of nitric oxide (NO), employing Mg-GTP as substrate in a concentration-dependent fashion, but was without effect on basal enzyme activity. Ca(2+) inhibited sGC stimulated by protoporphyrin IX or YC-1 suggesting that inhibition was not NO-dependent. In contrast, Ca(2+) was without effect on sGC activated by SNP employing Mn-GTP as substrate, demonstrating that inhibition did not reflect displacement of heme from sGC. Ligand activation of sGC unmasked negative allosteric sites of high (K(i) similar 10(-7) M) and low (K(i) approximately 10(-5) M) affinity for Ca(2+) that mediated noncompetitive and uncompetitive inhibition, respectively. Free Mg(2+) in excess of substrate did not alter the concentration-response relationship of Ca(2+) inhibition at high affinity sites, but produced a rightward shift in that relationship at low affinity sites. Similarly, Ca(2+) inhibition at high affinity sites was noncompetitive, whereas inhibition at low affinity sites was competitive, with respect to free Mg(2+). Purified sGC specifically bound (45)Ca(2+) in the presence of a 1000-fold excess of Mg(2+) and in the absence of activating ligands. These data suggest that sGC is a constitutive Ca(2+) binding protein whose allosteric function is conditionally dependent upon ligand activation.
AD  - Division of Clinical Pharmacology, Department of Medicine and Biochemistry, Thomas Jefferson University, Philadelphia, PA 19107, USA.
AU  - Kazerounian,S.
AU  - Pitari,G.M.
AU  - Ruiz-Stewart,I.
AU  - Schulz,S.
AU  - Waldman,S.A.
KW  - 0 (Nitric Oxide Donors)
KW  - 10102-43-9 (Nitric Oxide)
KW  - 15078-28-1 (Nitroprusside)
KW  - 7440-70-2 (Calcium)
KW  - EC 4.6.1.2 (Guanylate Cyclase)
KW  - Allosteric Regulation
KW  - Animal
KW  - Binding Sites
KW  - Binding, Competitive
KW  - Calcium [physiology]
KW  - Cattle
KW  - Enzyme Activation
KW  - Guanylate Cyclase [metabolism]
KW  - Kinetics
KW  - Lung [enzymology]
KW  - Nitric Oxide [physiology]
KW  - Nitric Oxide Donors [pharmacology]
KW  - Nitroprusside [pharmacology]
KW  - Support, Non-U.S. Gov't
KW  - Support, U.S. Gov't, P.H.S.
PY  - 2002///Mar 12
JA  - Biochemistry
VL  - 41
IS  - 10
SP  - 3396
EP  - 404
ER  - 

TY  - JOUR
TI  - YC-1-mediated vascular protection through inhibition of smooth muscle cell proliferation and platelet function.
N2  - YC-1, a synthetic benzyl indazole derivative, is capable of stimulating endogenous vessel wall cyclic guanosine monophosphate (cGMP) production and attenuating the remodeling response to experimental arterial angioplasty. In an effort to investigate the mechanisms of this YC-1-mediated vasoprotection, we examined the influence of soluble YC-1 or YC-1 incorporated in a polyethylene glycol (PEG) hydrogel on cultured rat vascular smooth muscle cell (SMC) cGMP synthesis, SMC proliferation, and platelet function. Results demonstrate that soluble YC-1 stimulated SMC cGMP production in a dose-dependent fashion, while both soluble and hydrogel-released YC-1 inhibited vascular SMC proliferation in a dose-dependent fashion without effects on cell viability. Platelet aggregation and adherence to collagen were both significantly inhibited in a dose-dependent fashion by soluble and hydrogel-released YC-1. Arterial neointima formation following experimental balloon injury was significantly attenuated by perivascular hydrogel-released YC-1. These results suggest that YC-1 is a potent, physiologically active agent with major anti-proliferative and anti-platelet properties that may provide protection against vascular injury through cGMP-dependent mechanisms.
AD  - Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, USA. dtulis@bcm.tmc.edu
AU  - Tulis,D.A.
AU  - Bohl Masters,K.S.
AU  - Lipke,E.A.
AU  - Schiesser,R.L.
AU  - Evans,A.J.
AU  - Peyton,K.J.
AU  - Durante,W.
AU  - West,J.L.
AU  - Schafer,A.I.
KW  - 0 (Hydrogels)
KW  - 0 (Indazoles)
KW  - 0 (Platelet Aggregation Inhibitors)
KW  - 0 (Polyethylene Glycols)
KW  - 154453-18-6 (3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole)
KW  - 7665-99-8 (Cyclic GMP)
KW  - Angioplasty, Balloon [adverse effects]
KW  - Animal
KW  - Arterial Occlusive Diseases [drug therapy]
KW  - Arterial Occlusive Diseases [etiology]
KW  - Arterial Occlusive Diseases [pathology]
KW  - Blood Platelets [drug effects]
KW  - Blood Platelets [physiology]
KW  - Carotid Stenosis [drug therapy]
KW  - Carotid Stenosis [etiology]
KW  - Carotid Stenosis [pathology]
KW  - Cell Adhesion [drug effects]
KW  - Cell Division [drug effects]
KW  - Cells, Cultured
KW  - Cyclic GMP [metabolism]
KW  - Dose-Response Relationship, Drug
KW  - Hydrogels [administration &amp; dosage]
KW  - Indazoles [administration &amp; dosage]
KW  - Indazoles [pharmacology]
KW  - Muscle, Smooth, Vascular [drug effects]
KW  - Muscle, Smooth, Vascular [metabolism]
KW  - Platelet Aggregation Inhibitors [administration &amp; dosage]
KW  - Platelet Aggregation Inhibitors [pharmacology]
KW  - Polyethylene Glycols [administration &amp; dosage]
KW  - Rats
KW  - Rats, Sprague-Dawley
KW  - Support, Non-U.S. Gov't
KW  - Support, U.S. Gov't, P.H.S.
PY  - 2002///Mar 8
JA  - Biochem Biophys Res Commun
VL  - 291
IS  - 4
SP  - 1014
EP  - 21
ER  - 

TY  - JOUR
TI  - Comparison of nitric oxide donors in lowering intraocular pressure in rabbits: role of cyclic GMP.
N2  - L-arginine-nitric oxide (NO) pathway participates in the physiology and in many pathological processes in the eye, such as glaucoma. The aim of the present study was to compare the ocular hypotensive effect of different NO-donors, and to get more information on the role of cyclic guanosine 3',5'-monophosphate (cGMP) in this process. The test compounds were administered topically or intravitreally in the eye of a normotensive rabbit. Intraocular pressure (IOP) was measured with a pneumatonometer after topical anesthesia. The metabolites of NO (nitrite, nitrate, NOx) and cGMP were assayed from the aqueous humor and plasma. NO-synthase (NOS) protein expression was assayed in the ciliary body by Western blotting. The maximal lowering of IOP was achieved as follows: atriopeptin III (concentration 78 (M, decrease in IOP 50%), atriopeptin 11 (84 (M, 37%). 8-Br-cGMP (90 mM, 37%), zaprinast + 8-Br-cGMP (1 mM + 90 mM, 34%), L-arginine (1 mM, 29%), SNP (40 mM, 28%), nitrosocaptopril (100 mM, 28%), S-nitrosothiol (SNOG) (10 mM, 27%), YC-1 (10 (M, 25%), zaprinast + SNP (1 mM + 40 mM, 22%), spermine NONOate (100 mM, 20%). The decrease in IOP lasted for 2-5 hr, except with atriopeptin II and III, when IOP values were first normalized in 6 hr and 2 days, respectively. In conclusion, the results of the present study indicate that by increasing the activity of L-arginine/NO/cGMP-pathway it is possible to lower IOP in rabbits equally to the currently used antiglaucomatous drugs.
AD  - Institute of Biomedicine, Biomedicum Helsinki, Pharmacology, University of Helsinki, Finland.
AU  - Kotikoski,H.
AU  - Alajuuma,P.
AU  - Moilanen,E.
AU  - Salmenpera,P.
AU  - Oksala,O.
AU  - Laippala,P.
AU  - Vapaatalo,H.
PY  - 2002///Feb
JA  - J Ocul Pharmacol Ther
VL  - 18
IS  - 1
SP  - 11
EP  - 23
ER  - 

TY  - JOUR
TI  - Nitric oxide modulates endotoxin-induced platelet-endothelial cell adhesion in intestinal venules.
N2  - Although platelets have been implicated in the pathogenesis of vascular diseases, little is known about factors that regulate interactions between platelets and the vessel wall under physiological conditions. The objectives of this study were to 1) define the contribution of nitric oxide (NO) to endotoxin (lipopolysaccharide, LPS)-induced platelet-endothelial cell (P/E) adhesion in murine intestinal venules and 2) determine whether the antiadhesive action of NO is mediated by soluble guanylate cyclase (sGC). Adhesive interactions between platelets and endothelial cells were monitored by intravital microscopy. LPS administration into control wild-type mice (WT) resulted in a &gt;15-fold increase in P/E adhesion. Similar responses were observed using endothelial NO synthase (eNOS)-deficient platelets. However, treatment with the NO donor diethylenetriamine-nitric oxide (DETA-NO) attenuated the P/E adhesion response to LPS, whereas the NO synthase inhibitor N(G)-nitro-L-arginine methyl ester or eNOS deficiency resulted in an exacerbation. P/E adhesion response did not differ between LPS-treated WT and inducible NOS-deficient mice. Inhibition of sGC abolished the attenuating effects of DETA-NO, whereas the sGC activator 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1) reduced LPS-induced P/E adhesion. These findings indicate that 1) eNOS-derived NO attenuates endotoxin-induced P/E adhesion and 2) sGC is responsible for the antiadhesive action of NO.
AD  - Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130-3932, USA.
AU  - Cerwinka,W.H.
AU  - Cooper,D.
AU  - Krieglstein,C.F.
AU  - Feelisch,M.
AU  - Granger,D.N.
KW  - 0 (Endotoxins)
KW  - 0 (Lipopolysaccharides)
KW  - 10102-43-9 (Nitric Oxide)
KW  - EC 1.14.13.- (endothelial constitutive nitric oxide synthase)
KW  - EC 1.14.13.- (inducible nitric oxide synthase)
KW  - EC 1.14.13.- (neural constitutive nitric oxide synthase)
KW  - EC 1.14.13.39 (Nitric-Oxide Synthase)
KW  - Animal
KW  - Endothelium, Vascular [drug effects]
KW  - Endothelium, Vascular [physiology]
KW  - Endotoxins [pharmacology]
KW  - Escherichia coli
KW  - Lipopolysaccharides [pharmacology]
KW  - Male
KW  - Mice
KW  - Mice, Inbred C57BL
KW  - Mice, Knockout
KW  - Microscopy, Fluorescence
KW  - Nitric Oxide [physiology]
KW  - Nitric-Oxide Synthase [deficiency]
KW  - Nitric-Oxide Synthase [genetics]
KW  - Nitric-Oxide Synthase [metabolism]
KW  - Platelet Adhesiveness [drug effects]
KW  - Support, U.S. Gov't, P.H.S.
KW  - Venules [drug effects]
KW  - Venules [physiology]
UR  - http://ajpheart.physiology.org/cgi/content/full/282/3/H1111
PY  - 2002///Mar
JA  - Am J Physiol Heart Circ Physiol
VL  - 282
IS  - 3
SP  - H1111
EP  - 7
ER  - 

TY  - JOUR
TI  - NO-independent regulatory site of direct sGC stimulators like YC-1 and BAY 41-2272.
N2  - BACKGROUND: The most important receptor for nitic oxide is the soluble guanylate cyclase (sGC), a heme containing heterodimer. Recently, a pyrazolopyridine derivative BAY 41-2272, structurally related to YC-1, was identified stimulating soluble guanylate cyclase in an NO-independent manner, which results in vasodilatation and antiplatelet activity. The study described here addresses the identification of the NO-independent site on soluble guanylate cyclase. RESULTS: We developed a photoaffinity label (3H-meta-PAL) for the direct and NO-independent soluble guanylate cyclase (sGC) stimulator BAY 41-2272 by introducing an azido-group into the tritium labeled compound. The synthesized photoaffinitylabel directly stimulates the purified sGC and shows in combination with NO a synergistic effect on sGC activity. Irradiation with UV light of 3H-meta-PAL together with the highly purified sGC leads to a covalent binding to the alpha1-subunit of the enzyme. This binding is blocked by unlabeled meta-PAL, YC-1 and BAY 41-2272. For further identification of the NO-independent regulatory site the 3H-meta-PAL labeled sGC was fragmented by CNBr digest. The 3H-meta-PAL binds to a CNBr fragment, consisting of the amino acids 236-290 of the alpha1-subunit. Determination of radioactivity of the single PTH-cycles from the sequencing of this CNBr fragment detected the cysteines 238 and 243 as binding residues of the 3H-meta-PAL. CONCLUSIONS: Our data demonstrate that the region surrounding the cysteines 238 and 243 in the alpha1-subunit of the sGC could play an important role in regulation of sGC activity and could be the target of this new type of sGC stimulators.
AD  - Pharma Research Center, Bayer AG, Wuppertal, Germany. johannes-peter.stasch.js@bayer-ag.de
AU  - Becker,E.M.
AU  - Alonso-Alija,C.
AU  - Apeler,H.
AU  - Gerzer,R.
AU  - Minuth,T.
AU  - Pleibeta,U.
AU  - Schmidt,P.
AU  - Schramm,M.
AU  - Schröder,H.
AU  - Schroeder,W.
AU  - Steinke,W.
AU  - Straub,A.
AU  - Stasch,J.P.
PY  - 2001///
JA  - BMC Pharmacol
VL  - 1
IS  - 1
ER  - 

TY  - JOUR
TI  - Soluble guanylyl cyclase activator YC-1 protects white matter axons from nitric oxide toxicity and metabolic stress, probably through Na(+) channel inhibition.
N2  - In the rat isolated optic nerve, nitric oxide (NO) activates soluble guanylyl cyclase (sGC), resulting in a selective accumulation of cGMP in the axons. The axons are also selectively vulnerable to NO toxicity. The experiments initially aimed to determine any causative link between these two effects. It was shown, using a NONOate donor, that NO-induced axonal damage occurred independently of cGMP. Unexpectedly, however, the compound YC-1, which is an allosteric activator of sGC, potently inhibited NO-induced axonopathy (IC(50) = 3 microM). This effect was not attributable to increased cGMP accumulation. YC-1 (30 microM) also protected the axons against damage by simulated ischemia, which (like NO toxicity) is sensitive to Na(+) channel inhibition. Although chemically unrelated to any known Na(+) channel inhibitor, YC-1 was effective in two biochemical assays for activity on Na(+) channels in synaptosomes. Electrophysiological recording from hippocampal neurons showed that YC-1 inhibited Na(+) currents in a voltage-dependent manner. At a concentration giving maximal protection of optic nerve axons from NO toxicity (30 microM), YC-1 did not affect normal axon conduction. It is concluded that the powerful axonoprotective action of YC-1 is unrelated to its activity on sGC but is explained by a novel action on voltage-dependent Na(+) channels. The unusual ability of YC-1 to protect axons so effectively without interfering with their normal function suggests that the molecule could serve as a prototype for the development of more selective Na(+) channel inhibitors with potential utility in neurological and neurodegenerative disorders.
AD  - The Wolfson Institute for Biomedical Research, University College London, London, United Kingdom. g.garthwaite@ucl.ac.uk
AU  - Garthwaite,G.
AU  - Goodwin,D.A.
AU  - Neale,S.
AU  - Riddall,D.
AU  - Garthwaite,J.
KW  - 0 (Enzyme Activators)
KW  - 0 (Indazoles)
KW  - 0 (Sodium Channel Blockers)
KW  - 0 (Sodium Channels)
KW  - 10102-43-9 (Nitric Oxide)
KW  - 154453-18-6 (3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole)
KW  - 50-99-7 (Glucose)
KW  - 7665-99-8 (Cyclic GMP)
KW  - 7782-44-7 (Oxygen)
KW  - EC 4.6.1.2 (Guanylate Cyclase)
KW  - Animal
KW  - Axons [drug effects]
KW  - Axons [metabolism]
KW  - Cyclic GMP [metabolism]
KW  - Drug Interactions
KW  - Enzyme Activators [pharmacology]
KW  - Glucose [metabolism]
KW  - Guanylate Cyclase [metabolism]
KW  - Indazoles [pharmacology]
KW  - Male
KW  - Nitric Oxide [toxicity]
KW  - Oxygen [metabolism]
KW  - Rats
KW  - Rats, Wistar
KW  - Sodium Channel Blockers [pharmacology]
KW  - Sodium Channels [metabolism]
KW  - Support, Non-U.S. Gov't
UR  - http://www.molpharm.org/cgi/content/full/61/1/97
PY  - 2002///Jan
JA  - Mol Pharmacol
VL  - 61
IS  - 1
SP  - 97
EP  - 104
ER  - 

TY  - JOUR
TI  - Role of conformational changes in the heme-dependent regulation of human soluble guanylate cyclase.
N2  - Soluble guanylate cyclase (sGC) is a receptor for endogenous and exogenous nitric oxide (NO) and is activated many fold upon its binding, making it a core enzyme in the nitric oxide signal transduction pathway. Much effort has been made to understand the link between binding of NO at the sGC heme and activation of the cyclase activity. We report here the first direct evidence for the role of conformational changes in transmitting the signal between the heme and cyclase domains. Using both circular dichroism (CD) and fluorescence spectroscopies, we have probed the effect that the sGC activators NO and 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl-indazole (YC-1) and the inhibitor 1H-[1,2,4]-oxadiazolo-[4,3-a]-quinoxalin-1-one (ODQ) have on the structure of the protein. Surprisingly, binding of either ODQ or YC-1 to NO-bound sGC cause virtually identical changes in the far-UV CD spectra of sGC, reflecting a perturbation in the secondary structure of the enzyme. This change is absent upon binding of NO, YC-1 or ODQ alone. Using this and previous data, we propose a working model for the mechanism of activation of sGC by NO and YC-1 and inhibition by ODQ.
AD  - Department of Chemistry and Biochemistry, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132-4163, USA.
AU  - Kosarikov,D.N.
AU  - Lee,J.M.
AU  - Uversky,V.N.
AU  - Counts Gerber,N.
KW  - 0 (Indazoles)
KW  - 0 (Nitric Oxide Donors)
KW  - 10102-43-9 (Nitric Oxide)
KW  - 14875-96-8 (Heme)
KW  - 154453-18-6 (3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole)
KW  - 73-22-3 (Tryptophan)
KW  - 79-06-1 (Acrylamide)
KW  - EC 4.6.1.2 (Guanylate Cyclase)
KW  - Acrylamide
KW  - Circular Dichroism
KW  - Enzyme Activation
KW  - Guanylate Cyclase [antagonists &amp; inhibitors]
KW  - Guanylate Cyclase [chemistry]
KW  - Heme [chemistry]
KW  - Human
KW  - Indazoles [chemistry]
KW  - Models, Chemical
KW  - Models, Molecular
KW  - Nitric Oxide [chemistry]
KW  - Nitric Oxide Donors [chemistry]
KW  - Protein Conformation
KW  - Protein Structure, Secondary
KW  - Spectrometry, Fluorescence
KW  - Support, Non-U.S. Gov't
KW  - Support, U.S. Gov't, P.H.S.
KW  - Tryptophan
PY  - 2001///Dec 15
JA  - J Inorg Biochem
VL  - 87
IS  - 4
SP  - 267
EP  - 76
ER  - 

TY  - JOUR
TI  - YC-1 activation of human soluble guanylyl cyclase has both heme-dependent and heme-independent components.
N2  - YC-1 [3-(5'-hydroxymethyl-2'furyl)-1-benzyl indazole] is an allosteric activator of soluble guanylyl cyclase (sGC). YC-1 increases the catalytic rate of the enzyme and sensitizes the enzyme toward its gaseous activators nitric oxide or carbon monoxide. In other studies the administration of YC-1 to experimental animals resulted in the inhibition of the platelet-rich thrombosis and a decrease of the mean arterial pressure, which correlated with increased cGMP levels. However, details of YC-1 interaction with sGC and enzyme activation are incomplete. Although evidence in the literature indicates that YC-1 activation of sGC is strictly heme-dependent, this report presents evidence for both heme-dependent and heme-independent activation of sGC by YC-1. The oxidation of the sGC heme by 1H-(1,2,4)oxadiazole(4,3-a)quinoxalin-1-one completely inhibited the response to NO, but only partially attenuated activation by YC-1. We also observed activation by YC-1 of a mutant sGC, which lacks heme. These findings indicate that YC-1 activation of sGC can occur independently of heme, but that activation is substantially increased when the heme moiety is present in the enzyme.
AD  - Department of Integrative Biology and Pharmacology, Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
AU  - Martin,Emil
AU  - Lee,Yu-Chen
AU  - Murad,Ferid
KW  - 0 (1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one)
KW  - 0 (DNA Primers)
KW  - 0 (Enzyme Activators)
KW  - 0 (Indazoles)
KW  - 0 (Oxadiazoles)
KW  - 0 (Quinoxalines)
KW  - 14875-96-8 (Heme)
KW  - 154453-18-6 (3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole)
KW  - EC 4.6.1.2 (Guanylate Cyclase)
KW  - Base Sequence
KW  - DNA Primers
KW  - Enzyme Activation
KW  - Enzyme Activators [pharmacology]
KW  - Guanylate Cyclase [metabolism]
KW  - Heme [metabolism]
KW  - Indazoles [pharmacology]
KW  - Oxadiazoles [pharmacology]
KW  - Oxidation-Reduction
KW  - Quinoxalines [pharmacology]
KW  - Solubility
KW  - Support, Non-U.S. Gov't
KW  - Support, U.S. Gov't, Non-P.H.S.
UR  - http://www.pnas.org/cgi/content/full/98/23/12938
PY  - 2001///Nov 6
JA  - Proc Natl Acad Sci U S A
VL  - 98
IS  - 23
SP  - 12938
EP  - 42
ER  - 

TY  - JOUR
TI  - Prolonged exposure to YC-1 induces apoptosis in adrenomedullary endothelial and chromaffin cells through a cGMP-independent mechanism.
N2  - YC-1, a benzyl indazole derivative, is an NO-independent direct activator of soluble guanylyl cyclase (sGC), which presents a synergistic action with NO in stimulating cGMP synthesis. These properties have served to suggest YC-1 as an attractive therapeutic agent by permitting the reduction of nitrovasodilator dosage and regulating endogenous cGMP metabolism. Here we studied the effect of prolonged exposure of adrenomedullary endothelial and chromaffin cells to YC-1. We found that YC-1 increased cGMP in the two types of cells and this action was blocked by the sGC inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ). Cells underwent apoptotic death in association with increased caspase-3-like activity, DNA fragmentation, cytoskeletal disorganization and changes in membrane permeability after prolonged incubation with YC-1. Caspase-3-like protease activity and DNA fragments in the cytoplasm were increased in a dose-dependent manner by 16 h YC-1 treatment. The specific and cell permeable caspase-3-like protease inhibitor DEVD-CHO effectively inhibited YC-1-mediated caspase-3-like activation and DNA fragmentation. Moreover, YC-1 also induced cell shape changes accompanied by actin filament disorganization and alterations in membrane permeability. Cells incubated for 24h with YC-1 showed damaged membranes by binding to nucleic acid of a dye excluded by the intact plasma membrane of live cells. YC-1 also induced a decrease in the intracellular non-specific esterase activity, another indication of cell toxicity. Apoptotic phenomena were not prevented by the presence of ODQ although it effectively inhibited the YC-1-elicited cGMP increases. These findings indicate that YC-1 induces apoptosis by activating caspase-3-like protease through a mechanism independent of sGC activation.
AD  - Departamento de Bioquimica, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040, Madrid, Spain.
AU  - Ferrero,R.
AU  - Torres,M.
KW  - 0 (Enzyme Activators)
KW  - 0 (Indazoles)
KW  - 154453-18-6 (3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole)
KW  - 7665-99-8 (Cyclic GMP)
KW  - Adrenal Medulla [cytology]
KW  - Adrenal Medulla [drug effects]
KW  - Adrenal Medulla [metabolism]
KW  - Animal
KW  - Apoptosis [drug effects]
KW  - Apoptosis [physiology]
KW  - Cattle
KW  - Cell Adhesion [drug effects]
KW  - Cell Size [drug effects]
KW  - Cells, Cultured
KW  - Chromaffin Cells [cytology]
KW  - Chromaffin Cells [drug effects]
KW  - Chromaffin Cells [metabolism]
KW  - Cyclic GMP [physiology]
KW  - Dose-Response Relationship, Drug
KW  - Endothelium [cytology]
KW  - Endothelium [drug effects]
KW  - Endothelium [metabolism]
KW  - Enzyme Activators [pharmacology]
KW  - Indazoles [pharmacology]
KW  - Intracellular Fluid [drug effects]
KW  - Intracellular Fluid [metabolism]
KW  - Support, Non-U.S. Gov't
KW  - Time Factors
PY  - 2001///Dec
JA  - Neuropharmacology
VL  - 41
IS  - 7
SP  - 895
EP  - 906
ER  - 

TY  - JOUR
TI  - Organic phosphates as a new class of soluble guanylate cyclase inhibitors.
N2  - This study aimed to examine effects of varied organic phosphates on activities of soluble guanylate cyclase (sGC). The enzyme was purified from bovine lung. Physiologically relevant concentrations of ATP, 2,3-bisphosphoglyceric acid and inositol hexakisphosphate inhibited its enzyme activities under steady-state conditions as well as those determined under stimulation with S-nitroso-N-acetylpenicillamine, a nitric oxide donor, carbon monoxide or YC-1. Lineweaver-Burk plot analyses revealed that these three organic phosphates act as competitive inhibitors. Other organic phosphates such as cardiolipin and sphingomyelin but not inorganic phosphates exhibited such inhibitory actions. These results suggest that organic phosphates serve as inhibitors for sGC-dependent signaling events.
AD  - Research Laboratory, Minophagen Pharmaceutical Co., Zama, Kanagawa, Japan. t-suzuki@sc.itc.keio.ac.jp
AU  - Suzuki,T.
AU  - Suematsu,M.
AU  - Makino,R.
KW  - 0 (Enzyme Activators)
KW  - 0 (Enzyme Inhibitors)
KW  - 0 (Indazoles)
KW  - 0 (Nitric Oxide Donors)
KW  - 0 (Organophosphorus Compounds)
KW  - 0 (S-nitro-N-acetylpenicillamine)
KW  - 10102-43-9 (Nitric Oxide)
KW  - 138-81-8 (2,3-Diphosphoglycerate)
KW  - 154453-18-6 (3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole)
KW  - 52-67-5 (Penicillamine)
KW  - 56-65-5 (Adenosine Triphosphate)
KW  - 630-08-0 (Carbon Monoxide)
KW  - 83-86-3 (Phytic Acid)
KW  - EC 4.6.1.2 (Guanylate Cyclase)
KW  - 2,3-Diphosphoglycerate [pharmacology]
KW  - Adenosine Triphosphate [pharmacology]
KW  - Animal
KW  - Binding, Competitive
KW  - Carbon Monoxide [pharmacology]
KW  - Cattle
KW  - Enzyme Activators [pharmacology]
KW  - Enzyme Inhibitors [pharmacology]
KW  - Guanylate Cyclase [antagonists &amp; inhibitors]
KW  - In Vitro
KW  - Indazoles [pharmacology]
KW  - Kinetics
KW  - Nitric Oxide [metabolism]
KW  - Nitric Oxide Donors [pharmacology]
KW  - Organophosphorus Compounds [pharmacology]
KW  - Penicillamine [analogs &amp; derivatives]
KW  - Penicillamine [pharmacology]
KW  - Phytic Acid [pharmacology]
KW  - Signal Transduction [drug effects]
KW  - Solubility
KW  - Support, Non-U.S. Gov't
PY  - 2001///Oct 19
JA  - FEBS Lett
VL  - 507
IS  - 1
SP  - 49
EP  - 53
ER  - 
