Developmental changes in the pulmonary circulation: role of the nitric oxide/ soluble guanylate cyclase/cyclic GMP and the isoprostane pathways

Background: We have shown that inhibition of cyclic GMP-phosphodiesterase 5A (PDE5A) by sildenafil (SIL) blunts cardiomyocyte β-adrenergic stimulation, but this effect depends on the activity of endothelial nitric oxide synthase (eNOS) to generate a specific pool of cyclic GMP. PDE5A normally localizes at Z-bands in myocytes, but localization is more diffuse in cells with eNOS chronically inhibited. Here, we tested whether the influence of eNOS on PDE5A localization and anti-adrenergic action depends upon cyclic GMP. Methods and Results: Mouse in vivo hemodynamics were assessed by pressure-volume analysis. Isoproterenol (ISO: 20 ng/kg/min, iv ) stimulated contractility was inhibited by SIL (100 μg/kg/min, iv ), however this did not occur in mice given N w -nitro-L-arginine methyl ester (L-NAME: 1 mg/mL in drinking water for 1 week) to inhibit NOS. Myocytes transfected with an adenoviral vector encoding a fusion protein (PDE5A-DSred) in vivo were subsequently isolated and examined for PDE5A/α-actinin localization. Normal cells showed strong co-localization, whereas L-NAME-treated cells had diffuse PDE5A distribution. If L-NAME was stopped for 1-wk washout, SIL regained anti-adrenergic activity, and PDE5A z-band localization was restored. If L-NAME was continued but combined with Bay 41– 8543 (BAY: 30 mg/kg/day, po ), a soluble guanylate cyclase (sGC) activator, both PDE5A localization and SIL anti-adrenergic action were also restored. Chronic L-NAME suppressed phosphorylation of vasodilator-stimulated protein (VASP), a marker of protein kinase G (PKG) activity, in hearts acutely exposed to ISO+SIL. After L-NAME washout or L-NAME+BAY, VASP phosphorylation with ISO+SIL was restored. Conclusion: NOS-dependent modulation of both PDE5A sarcomere localization and anti-adrenergic activity depends upon sGC-derived cyclic GMP, and is linked to PKG activation. This suggests sGC activators may have synergistic effects with PDE5A inhibitors.

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Hemodynamic Effects of a Soluble Guanylate Cyclase Stimulator, Riociguat, and an Activator, Cinaciguat, During NO-Modulation in Healthy Pigs

Journal of Cardiovascular Pharmacology and Therapeutics ◽

10.1177/1074248420940897 ◽

2020 ◽

Vol 26 (1) ◽

pp. 75-87

Author(s):

Torvind Næsheim ◽

Ole-Jakob How ◽

Truls Myrmel

Keyword(s):

Nitric Oxide ◽

Guanylate Cyclase ◽

Pulmonary Circulation ◽

High Throughput Screening ◽

Soluble Guanylate Cyclase ◽

Vascular Control ◽

Vascular Effects ◽

Vast Number ◽

Systolic And Diastolic Function

Cardiovascular diseases are often characterized by dysfunctional endothelium. To compensate for the related lack of nitric oxide (NO), a class of soluble guanylate cyclase (sGC) stimulators and activators have been developed with the purpose of acting downstream of NO in the NO-sGC-cGMP cascade. These drugs have been discovered using photoaffinity labeling of sGC and high-throughput screening of a vast number of chemical compounds. Therefore, an understanding of the integrated physiological effects of these drugs in vivo is necessary on the path to clinical application. We have characterized the integrated hemodynamic impact of the sGC stimulator riociguat and the activator cinaciguat in different NO-states in healthy juvenile pigs (n = 30). We assessed the vascular effects in both systemic and pulmonary circulation, the contractile effects in the right and left ventricles, and the effects on diastolic cardiac functions. Nitric oxide-tone in these pigs were set by using the NO-blocker l-NAME and by infusion of nitroglycerine. The studies show a more pronounced vasodilatory effect in the systemic than pulmonary circulation for both drugs. Riociguat acts integrated with NO in an additive manner, while cinaciguat, in principle, completely blocks the endogenous NO effect on vascular control. Neither compound demonstrated pronounced cardiac effects but had unloading effect on both systolic and diastolic function. Thus, riociguat can potentially act in various disease states as a mean to increase NO-tone if systemic vasodilation can be balanced. Cinaciguat is a complicated drug to apply clinically due to its almost complete lack of integration in the NO-tone and balance.

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Soluble guanylate cyclase and nitric oxide synthase in synaptosomal fractions of bovine retina

Visual Neuroscience ◽

10.1017/s0952523898155098 ◽

1998 ◽

Vol 15 (5) ◽

pp. 867-873 ◽

Cited By ~ 4

Author(s):

ALEXANDER MARGULIS ◽

NIKOLAY POZDNYAKOV ◽

LOAN DANG ◽

ARI SITARAMAYYA

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Guanylate Cyclase ◽

Cyclic Gmp ◽

Soluble Guanylate Cyclase ◽

Cyclase Activity ◽

Inner Retina ◽

Synaptosomal Fraction ◽

Oxide Synthase ◽

Plexiform Layers

Cyclic GMP has been shown in recent years to directly activate ion channels in bipolar and ganglion cells, and to indirectly regulate coupling between horizontal cells, and between bipolar and amacrine cells. In all of these cases, the effects of cyclic GMP are mimicked by nitric oxide. An increase in calcium concentration stimulates the production of nitric oxide by neuronal and endothelial forms of nitric oxide synthase, which in turn activates soluble guanylate cyclases, enhancing the synthesis of cyclic GMP. Though some effects of nitric oxide do not involve cyclic GMP, the nitric oxide-cyclic GMP cascade is well recognized as a signaling mechanism in brain and other tissues. The widespread occurrence of nitric oxide/cyclic GMP-regulated ion channel activity in retinal neurons raises the possibility that nitric-oxide-sensitive soluble guanylate cyclases play an important role in cell–cell communication, and possibly, synaptic transmission. Immunohistochemical studies have indicated the presence of soluble guanylate cyclase in retinal synaptic layers, but such studies are not suitable for determination of the density or quantitative subcellular distribution of the enzyme. Microanalytical methods involving microdissection of frozen retina also showed the presence of cyclase activity in retinal plexiform layers but these methods did not permit distinction between nitric oxide-sensitive and insensitive cyclases. In this study, we fractionated retinal homogenate into the cytosolic and synaptosomal fractions and investigated the specific activity and distribution of soluble guanylate cyclase and nitric oxide synthase. The results show that both enzymes are present in the synaptosomal fractions derived from inner and outer plexiform layers. The synaptosomal fraction derived from inner retina was highly enriched in cyclase activity. Nitric oxide synthase activity was also higher in the inner than outer retinal synaptosomal fraction. The results suggest that the nitric oxide-cyclic GMP system is operational in both synaptic layers of retina and that it may play a more significant role in the inner retina.

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The role of nitric oxide in the regulation of the electrical activity of the trigeminal nerve in the rat

10.34014/mpphe.2021-177-180 ◽

2021 ◽

Author(s):

S.O. Svitko ◽

K.S. Koroleva ◽

G.F. Sitdikova ◽

K.A. Petrova

Keyword(s):

Nitric Oxide ◽

Sodium Nitroprusside ◽

Trigeminal Nerve ◽

Guanylate Cyclase ◽

Soluble Guanylate Cyclase ◽

No Synthase ◽

The Body ◽

No Donor ◽

No Signaling

Nitric oxide (NO) is a gaseous signaling molecule that regulates a number of physiological functions, including its role in the formation of migraine has been established. NO is endogenously produced in the body from L-arginine by NO synthase. The NO donor, nitroglycerin, is a trigger of migraine in humans and is widely used in the modeling of this disease in animals, which suggests the involvement of components of the NO signaling cascade in the pathogenesis of migraine. Based on the results obtained, it was found that an increase in the concentration of both the substrate for the synthesis of NO, L-arginine, and the NO donor, sodium nitroprusside, has a pro-nociceptive effect in the afferents of the trigeminal nerve. In this case, the effect of sodium nitroprusside is associated with the activation of intracellular soluble guanylate cyclase. Key words: nitric oxide, migraine, trigeminal nerve, L-arginine, guanylate cyclase, sodium nitroprusside, nociception.

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Interleukin 1 and endotoxin activate soluble guanylate cyclase in vascular smooth muscle

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1990.259.1.r38 ◽

1990 ◽

Vol 259 (1) ◽

pp. R38-R44 ◽

Cited By ~ 5

Author(s):

D. Beasley

Keyword(s):

Nitric Oxide ◽

Guanylate Cyclase ◽

Soluble Guanylate Cyclase ◽

Interleukin 1 ◽

Physiological Salt Solution ◽

Initial Exposure ◽

Vasodilatory Action ◽

Ly 83583

Our recent studies indicate that interleukin 1 (IL-1) and bacterial lipopolysaccharide inhibit agonist-induced contractions in rat aortic rings by an endothelium-independent mechanism. The present study investigated the role of guanosine 3',5'-cyclic monophosphate (cGMP) in the vasodilatory action of IL-1 and endotoxin. Rat aortic rings were denuded of endothelium and incubated for 3 h in physiological salt solution containing no additions, IL-1 (20 ng/ml), or endotoxin (10 micrograms/ml). Contractions induced by phenylephrine (3 x 10(-7) M) were decreased by 40 and 85% in endotoxin- and IL-1-treated rings, respectively. IL-1 increased cGMP content 2.5-fold in the absence of and 5.5-fold in the presence of 3-isobutyl-1-methylxanthine (IBMX). Endotoxin also increased cGMP content in the absence and presence of IBMX (5.5- and 25-fold, respectively). Both IL-1- and endotoxin-induced increases in cGMP occurred 3-4 h after initial exposure. The guanylate cyclase inhibitors, LY 83583 and methylene blue, each abolished IL-1- and endotoxin-induced inhibition of contraction and IL-1-induced production of cGMP. Furthermore, hemoglobin, which binds nitric oxide, completely blocked IL-1-induced increases in cGMP. We conclude that IL-1 and endotoxin inhibit vascular contraction in vitro by increasing aortic cGMP content. Studies with inhibitors suggest IL-1 and endotoxin may induce endothelium-independent production of nitric oxide or another free radical that activates soluble guanylate cyclase.

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N-hydroxylamine is not an intermediate in the conversion of l-arginine to an activator of soluble guanylate cyclase in neuroblastoma N1E-115 cells

Biochemical Journal ◽

10.1042/bj2730547 ◽

1991 ◽

Vol 273 (3) ◽

pp. 547-552 ◽

Cited By ~ 6

Author(s):

S Pou ◽

W S Pou ◽

G M Rosen ◽

E E el-Fakahany

Keyword(s):

Guanylate Cyclase ◽

Cyclic Gmp ◽

Soluble Guanylate Cyclase ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Intact Cells ◽

Relaxing Factor ◽

Endothelium Derived Relaxing Factor ◽

Dose Dependent

This study evaluates the role of N-hydroxylamine (NH2OH) in activating soluble guanylate cyclase in the mouse neuroblastoma clone N1E-115. It has been proposed that NH2OH is a putative intermediate in the biochemical pathway for the generation of nitric oxide (NO)/endothelium-derived relaxing factor (EDRF) from L-arginine. NH2OH caused a time- and concentration-dependent increase in cyclic GMP formation in intact cells. This response was not dependent on Ca2+. In cytosol preparations the activation of guanylate cyclase by L-arginine was dose-dependent and required Ca2+ and NADPH. In contrast, NH2OH itself did not activate cytosolic guanylate cyclase but it inhibited the basal activity of this enzyme in a concentration-dependent manner. The formation of cyclic GMP in the cytosolic fractions in response to NH2OH required the addition of catalase and H2O2. On the other hand, catalase and/or H2O2 lead to a decrease in L-arginine-induced cyclic GMP formation. Furthermore, NH2OH inhibited L-arginine- and sodium nitroprusside-induced cyclic GMP formation in the cytosol. The inhibition of L-arginine-induced cyclic GMP formation in the cytosol by NH2OH was not reversed by the addition of superoxide dismutase. These data strongly suggest that NH2OH is not a putative intermediate in the metabolism of L-arginine to an activator of guanylate cyclase.

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Vasorelaxant and antiplatelet activity of 4,7-dimethyl-1,2,5-oxadiazolo[3,4-d ]pyridazine 1,5,6-trioxide: role of soluble guanylate cyclase, nitric oxide and thiols

British Journal of Pharmacology ◽

10.1038/sj.bjp.0703156 ◽

2000 ◽

Vol 129 (6) ◽

pp. 1163-1177 ◽

Cited By ~ 33

Author(s):

Alexander Ya Kots ◽

Mikhail A Grafov ◽

Yuri V Khropov ◽

Vasily L Betin ◽

Natalya N Belushkina ◽

...

Keyword(s):

Nitric Oxide ◽

Guanylate Cyclase ◽

Soluble Guanylate Cyclase ◽

Antiplatelet Activity

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Immunohistochemical demonstration of a paracrine role of nitric oxide in bronchial function

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1994.267.6.l704 ◽

1994 ◽

Vol 267 (6) ◽

pp. L704-L711 ◽

Cited By ~ 6

Author(s):

A. Rengasamy ◽

C. Xue ◽

R. A. Johns

Keyword(s):

Nitric Oxide ◽

Monoclonal Antibody ◽

Endothelial Cells ◽

Smooth Muscle ◽

Guanylate Cyclase ◽

Soluble Guanylate Cyclase ◽

Raw 264.7 Macrophages ◽

Aortic Endothelial Cells ◽

Arterial Endothelial Cells

We addressed the controversial role of nitric oxide (NO) in bronchial function by an immunohistochemical study of the localization of NO synthase (NOS) and its effector protein, soluble guanylate cyclase, in rat bronchus. For this study, a monoclonal antibody to the bovine constitutive neuronal NOS was developed and characterized. In Western blot analysis, this monoclonal antibody (anti-NOS antibody) reacted with bovine cerebellum NOS (150 kDa) as well as with structurally different NOSs from cultured bovine aortic endothelial cells (130 kDa) and cultured RAW 264.7 macrophages (130 kDa). The reactivity of anti-NOS antibody was confirmed by immunohistochemical staining of rat cerebellum, arterial endothelial cells, and cultured stimulated macrophages. When the distribution of NOS in rat airway was characterized, the anti-NOS antibody showed immunoreactivity within respiratory epithelium but not in the bronchial smooth muscle. The NADPH-diaphorase staining correlated with the immunostaining. In contrast, a monoclonal antibody to the rat lung-soluble guanylate cyclase immunostained respiratory smooth muscle but not epithelium. This study suggests a paracrine role for NO in bronchial function analogous to the function of the NOS-soluble guanylate cyclase pathway in blood vessels.

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