Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.6.1.2 (guanylate cyclase)
 8,497 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

S-Nitrosoglutathione and sodium nitroprusside, two activators of the soluble guanylate cyclase, inhibit the intracellular calcium rise evoked by thrombin at an early step of the activation cascade. A similar effect is obtained with prostaglandin E1, a drug that increases cAMP. We have found that in human platelets thrombin 0.1 IU/ml (approximately 1 nmol/l) produced a transient increase of [Ca2+]i. After a 10-min preincubation at 37 degrees C in 100 mumol/l S-nitrosoglutathione the peak value was reduced by 79 +/- 4% (mean and SEM, percentage of the parallel control). The [Ca2+]i peak was reduced by 66 +/- 4% after preincubation in 100 mumol/l sodium nitroprusside, and by 90 +/- 2% after preincubation in 10 mumol/l prostaglandin E1. Thrombin has a slow alkalizing effect. After a 10-min preincubation at 37 degrees C in 100 mumol/l S-nitrosoglutathione the change in pHi produced by thrombin was reduced by 35 +/- 5%, but only 12 +/- 4% after preincubation in 100 mumol/l sodium nitroprusside. The alkalizing effect of thrombin was also blunted by 10 mumol/l prostaglandin E1: the change of intracellular pH was decreased by 39 +/- 5%. As a conclusion, these drugs in addition to the reduction of rise in [Ca2+]i have an inhibitory effect on the alkalizing response induced by thrombin.
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PMID:Attenuation of alkalizing effect of thrombin by S-nitrosoglutathione in human platelets. 1093 98

In vascular smooth muscle cells, NO stimulates the synthesis of cGMP by soluble guanylate cyclase (sGC), a heterodimer composed of alpha(1) and beta(1) subunits. NO/cGMP signal transduction affects multiple cell functions that contribute to neointima formation after vascular injury. Balloon-induced vascular injury was found to decrease sGC subunit expression and enzyme activity in rat carotid arteries. The effect of restoring sGC enzyme activity on neointima formation was investigated using recombinant adenoviruses specifying sGC alpha(1) and beta(1) subunits (Adalpha1 and Adbeta1). Coinfection of cultured rat aortic smooth muscle cells with Adalpha1 and Adbeta1 increased NO-stimulated intracellular cGMP levels 60-fold and decreased DNA synthesis and migration by 16% and 48%, respectively. Immunoreactivity for alpha(1) and beta(1) subunits colocalized in carotid arteries infected with Adalpha1 and Adbeta1. Molsidomine-stimulated carotid tissue cGMP levels were greater after coinfection with Adalpha1 and Adbeta1 than after infection with a control virus, AdRR5 (0.53+/-0.09 pmol/mg protein, mean+/-SEM, versus 0.23+/-0.09, P<0.05). Mean intima/media ratio, 2 weeks after balloon injury and twice-daily administration of 5 mg/kg molsidomine, was less in rats coinfected with Adalpha1 and Adss1 than in rats infected with AdRR5 or in uninfected rats (0.36+/-0.11 versus 0. 81+/-0.13 and 0.75+/-0.25, respectively, P<0.05). Thus, Adalpha1 and Adbeta1 gene transfer to balloon-injured rat carotid arteries increases NO responsiveness and attenuates neointima formation via a direct antiproliferative and antimigratory effect on vascular smooth muscle cells.
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PMID:Soluble guanylate cyclase alpha(1) and beta(1) gene transfer increases NO responsiveness and reduces neointima formation after balloon injury in rats via antiproliferative and antimigratory effects. 1113 81

Nitric oxide (NO) is known to modulate platelet adhesion and aggregation, which are both mediated by fibrinogen receptor glycoprotein (GP)IIb/IIIa. To investigate effects of NO on GPIIb/IIIa activation and inactivation, platelets were exposed to NO donor 3-morpholino-sydnonimine (SIN-1) before and after stimulation with different agonists: thromboxane analog U-46619, epinephrine, adenosine diphosphate, human a-thrombin, and phorbol-12-myristate-13-acetate (0.02 micromol/l). (1) Flow cytometry analysis of SIN-1-pre-incubated samples using PAC-1 monoclonal antibody revealed an inhibition of receptor activation by 80.9 +/- 1.2, 71.3 +/- 1.8, 56 +/- 4.9, 87 +/- 3.4, and 56 +/- 5% (mean +/- SEM, relative to baseline). (2) Administration of SIN-1 after stimulation reversed receptor activation by 55 +/- 5.2, 56 +/- 2.0, 53 +/- 5.4, 42 +/- 4.3, and 44 +/- 5%, respectively. With 0.1 micromol/l phorbol-12-myristate-13-acetate, GPIIb/IIIa activation was irreversible. (3) SIN-1 effects could completely be blocked by equimolar addition of guanylyl cyclase inhibitor 1H(1,2,4)oxadiazolo(4,3-alpha)quinoxalin-1-on. (4) Spontaneous receptor closure after activation with human alpha-thrombin and adenosine diphosphate was not due to platelet-derived NO; SIN-1, however accelerated spontaneous receptor inactivation. (5) SIN-1-inactivated receptors still responded to stimulation. In conclusion, SIN-1 or NO modulates GPIIb/IIIa conformational change in vitro via guanosine 3',5'-monophosphate-dependent pathways. Whereas spontaneous receptor inactivation may be enhanced by exogenous NO, platelet-derived NO is not involved in receptor inactivation.
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PMID:Inactivation of platelet glycoprotein IIb/IIIa receptor by nitric oxide donor 3-morpholino-sydnonimine. 1294 73


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