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)

Patients with systemic hypertension of various etiologies maintain their pulmonary artery pressures within normal limits. We have reported in isolated perfused rat lungs that low basal tone appears to be regulated by nitric oxide (NO)-dependent and -independent mechanisms of soluble guanylate cyclase activation, and similar results are seen in isolated small pulmonary arteries (PA) from these animals. The abdominal aorta of rats was ligated above the left and below the right renal artery (aortic coarctation, AC). The mean arterial pressure (MAP) and pulmonary artery pressure (PAP) of 24-h post-AC rats (MAP 123 +/- 7.1 mm Hg and PAP 4.2 +/- 0.9 mm Hg) showed no significant change when compared with those of sham control rats (MAP 116 +/- 7.0 mm Hg and PAP 5.0 +/- 0.04 mm Hg). Hypoxic contractions in isolated small rat PA (160 to 260 microns diameter) were significantly increased from 56.7 +/- 12.0 mg in the control group to 139 +/- 31 mg in the 24-h post-AC rats (P < 0.05). PA contractions in the presence of 100 microM nitro-L-arginine (NLA) increased from 102 +/- 34 mg among the sham control group to 261 +/- 30 mg among the 24-h post AC rats (P < 0.05). After NLA, the hypoxic contractions decreased to 15 +/- 2.9 mg in the control rats and 45 +/- 16 mg in the 24-h post-AC rats when compared with pre-NLA values (P < 0.05). Western and Northern blotting of protein and messenger ribonucleic acid (mRNA) extracted from the whole rat lung showed a significant rise in endothelial cell nitric oxide synthase (EcNOS; 207 +/- 34%) and EcNOS mRNA (2-fold) when comparing controls with 24-h post-AC rats. These data indicate that there is increased EcNOS activity and synthesis that maintain low PA tone in these rat models as early as 24 h after AC; in addition, this effect is independent of the systemic blood pressure.
 ...
PMID:Early regulatory changes in rat pulmonary artery of renin-dependent systemic hypertension models. 887 80

We have recently reported in normal isolated-perfused rat lungs that low basal tone appears to be regulated by nitric oxide (NO)-dependent and -independent mechanisms of soluble guanylate cyclase activation. In this study, we examined the role of NO in the regulation of pulmonary artery (PA) tone from rats with renin-dependent hypertension. Rats were made hypertensive by ligating the abdominal aorta above the left and below the right renal artery (aortic coarctation, AC). Mean arterial pressure significantly increased from 119 +/- 8.4 mmHg in control animals to 156 +/- 15 mmHg 7-14 days after AC surgery. PA pressures, however, remained unchanged (8.5 +/- 3.4 mmHg in control animals vs. 11 +/- 3.3 mmHg in AC animals). Hypoxic contractions in U-46619 precontracted isolated small PA (160-260 microns diameter) were significantly increased from 51 +/- 13 mg in the control group to 142 +/- 38 mg (P < or = 0.05) in AC animals. Nitro-L-arginine (NLA; 100 microM) contractions were also enhanced in the AC animal. The enhanced NLA response may correlate with an increase in endothelial cell NO synthase (NOS) as detected by Western blotting (132 +/- 28% of control; P < 0.05). These data suggest that, in this renin-dependent model of systemic hypertension, there is increased endothelial cell NOS activity that maintains low PA tone, preventing the lung from developing increased pressures.
 ...
PMID:Peripheral hypertension and alterations in pulmonary vascular regulation. 925 47

This study was performed to investigate whether the expression of p21(Sdi1/Cip1/Waf1), one of the cyclin-dependent kinase inhibitor proteins, could be regulated by nitric oxide (NO) and might account for the antiproliferative effect of NO. Quiescent adventitial fibroblasts were stimulated to proliferate by serum addition and by NO donors added during different phases of the cell cycle. [(3)H]Thymidine incorporation was markedly reduced by S-nitroso-N-acetyl-penicillamine (SNAP) added either with serum at quiescence or at later time point in the cell cycle. Northern and Western blot analyses showed that addition of SNAP either at quiescence or 15 hours after serum addition induced a rapid induction of p21 mRNA and protein. Immunoprecipitation studies and electrophoretic mobility shift analysis indicate that the treatment of cells with SNAP induced the phosphorylation of p53 (a tumor suppressor protein) and enhanced the ability of p53 to bind DNA when SNAP was added during the cell cycle. The increased expression of p21 mRNA or p53 activation during late G(1) or S phase was also caused by addition of 8-bromo-cGMP and effectively blocked by a specific inhibitor of the soluble guanylate cyclase. Furthermore, this response to SNAP was blocked by an inhibitor of protein kinase G. These studies implicate NO as a potential regulator of the cell cycle in aortic adventitial fibroblasts through a cGMP-mediated transcriptional mechanism involving the induction of p21.
 ...
PMID:Nitric oxide-induced increase in p21(Sdi1/Cip1/Waf1) expression during the cell cycle in aortic adventitial fibroblasts. 1063 97

The cytoplasmic or soluble forms of guanylyl cyclase (sGC) are heme-containing heterodimeric enzymes that are regulated by nitric oxide (NO) and carbon monoxide (CO). These gaseous messenger molecules are produced in the human placenta and are potential regulators of vasodilation and trophoblast invasion. The alpha(2)-subunit of sGC has only recently been shown to naturally occur in placental extracts. In the present study, two novel antibodies directed against different epitopes of the alpha(2) subunit, were generated. Western Blot analysis confirmed the presence of a 82 kDa protein, identical with alpha(2) protein overexpressed in Sf9 cells. According to RNase protection analysis the alternatively spliced alpha(2i) variant was absent from human placenta. Immunohistochemical analysis showed the presence of alpha(2) protein in syncytiotrophoblast and villous and umbilical blood vessels, which are known sites of NO production. Strong expression was observed in the extravillous (intermediate) trophoblast, where the expression of CO-generating hemeoxygenases has recently been documented. Localization of alpha(2) subunit expression suggests a role for sGC in mediating the actions of both NO and CO. The novel antibodies characterized in the present study will be powerful tools to further elucidate the role of the NO/CO/cGMP signaling pathways in pathologic states such as preeclampsia and intrauterine growth retardation.
 ...
PMID:Expression and tissue localization of soluble guanylyl cyclase in the human placenta using novel antibodies directed against the alpha(2) subunit. 1115 65

Apoptosis is thought to play an important regulatory role in placental development and inappropriate trophoblast apoptosis has been implicated in complications of pregnancy such as pre-eclampsia. Here we show that apoptosis of a human extravillous trophoblast-derived cell line (SGHPL-4) can be regulated by nitric oxide (NO). Nitric oxide produced exogenously by the addition of NO donors was able to delay or inhibit apoptosis induced by a combination of tumour necrosis factor alpha and actinomycin D and to suppress the activity of caspase 3. Treatment with hepatocyte growth factor (HGF) stimulated expression of the inducible isoform of NO synthase and was also able to protect SGHPL-4 cells from caspase 3 activation and apoptosis. The inhibition of basal NO production with NO synthase inhibitors was shown to sensitise cells to apoptotic stimuli and to reduce the level of endogenous caspase 3 nitrosylation. The anti-apoptotic effects of NO in these extravillous trophoblast cells appear to be mediated through the production of cyclic GMP as inhibitors of soluble guanylate cyclase inhibited the protective effect of both HGF and NO donors.
 ...
PMID:Nitric oxide protects human extravillous trophoblast cells from apoptosis by a cyclic GMP-dependent mechanism and independently of caspase 3 nitrosylation. 1283 87

We previously reported that initiation of metamorphosis of larvae of Lytechinus pictus is negatively regulated by nitric oxide (NO) and cGMP. We have examined the expression of nitric oxide synthase (NOS) and cGMP in cells of the developing larva. A section of the post-oral ciliary band of feeding larvae includes neural cells defined by their expression of both NOS and the echinoderm neural-specific antibody 1E11. These neurons project processes to the pre-oral neuropile during larval development. Larvae regenerated this section of the ciliary band after its excision, complete with NOS-defined neurons that projected again to the pre-oral neuropile. Excision of ectoderm containing the post-oral ciliary band prevented a behavioral and morphogenetic response of competent larvae to biofilm, and delayed initiation of metamorphosis. Elevated cGMP levels were detected in several larval and juvenile cell types prior to metamorphosis. Treatment of larvae with ODQ, an inhibitor of soluble guanylate cyclase, decreased cGMP levels and induced metamorphosis while a generator of NO counteracted this effect, indicating inhibition of metamorphosis by NO operates via interaction with soluble guanylate cyclase. We discuss these observations, proposing that the NOS-defined neurons in the post-oral ciliary band have a chemosensory function during settlement and metamorphosis that involves morphologically specialized ectoderm and manipulation of fluid flow. We provide a tentative cellular model of how environmental signals may be transduced into a metamorphic response.
 ...
PMID:Development of nitric oxide synthase-defined neurons in the sea urchin larval ciliary band and evidence for a chemosensory function during metamorphosis. 1747 25

Endothelium-dependent relaxations are predominantly regulated by nitric oxide (NO) in large conduit arteries and by endothelium-dependent hyperpolarization (EDH) in small resistance vessels. Although the nature of EDH factors varies depending on species and vascular beds, we have previously demonstrated that endothelial NO synthases (eNOS)-derived hydrogen peroxide (H2O2) is an EDH factor in animals and humans. This vessel size-dependent contribution of NO and EDH is, at least in part, attributable to the diverse roles of endothelial NOSs system; in large conduit arteries, eNOS mainly serves as a NO-generating system to elicit soluble guanylate cyclase-cyclic guanosine monophosphate-mediated relaxations, whereas in small resistance vessels, it serves as a superoxide-generating system to cause EDH/H2O2-mediated relaxations. Endothelial caveolin-1 may play an important role for the diverse roles of NOSs. Although reactive oxygen species are generally regarded harmful, the physiological roles of H2O2 have attracted much attention as accumulating evidence has shown that endothelium-derived H2O2 contributes to cardiovascular homeostasis. The diverse functions of endothelial NOSs system with NO and EDH/H2O2 could account for a compensatory mechanism in the setting of endothelial dysfunction. In this review, we will briefly summarize the current knowledge on the diverse functions of endothelial NOSs system: NO and EDH/H2O2.
 ...
PMID:Diverse Functions of Endothelial NO Synthases System: NO and EDH. 2664 19