scholarly journals Activation of the nitric oxide-cGMP pathway reduces phasic contractions in neonatal rat bladder strips via protein kinase G

2009 ◽  
Vol 297 (2) ◽  
pp. F333-F340 ◽  
Author(s):  
Debra E. Artim ◽  
F. Aura Kullmann ◽  
Stephanie L. Daugherty ◽  
Hsi-Yang Wu ◽  
William C. de Groat
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase ◽  
Soluble Guanylyl Cyclase ◽  
Inhibitory Effect ◽  
Neonatal Rat ◽  
Protein Kinase G ◽  
No Donor ◽  
Adult Rat ◽  
Rat Bladder ◽  
Normal Bladder

Nitric oxide (NO), a neurotransmitter in the lower urinary tract, stimulates soluble guanylyl cyclase (sGC) and in turn cGMP-dependent protein kinase G (PKG) to modulate a number of downstream targets. NO donors reduce bladder hyperactivity in some pathological models but do not affect normal bladder activity in the adult rat. In this study, the NO donor S-nitroso- N-acetyl-dl-penicillamine (SNAP; 100 μM) decreased the amplitude and frequency of spontaneous and carbachol-enhanced contractions in neonatal rat bladder strips, which are intrinsically hyperactive. This effect was blocked by inhibition of sGC and mimicked by application of a membrane-permeable cGMP analog (8-bromo-cGMP, 100 μM). Inhibition of PKG prevented or reversed the inhibitory effects of 8-bromo-cGMP. A portion of the SNAP-mediated inhibition was also dependent upon PKG; however, a short-lasting, sGC-dependent inhibitory effect of SNAP was still present after PKG inhibition. Inhibition of NO synthase with l-NAME (100 μM) did not change the amplitude or frequency of contractions. However, inhibition of endogenous phosphodiesterase (PDE)-5 with zaprinast (25 μM) reduced the amplitude and frequency of phasic contractions and increased the magnitude of inhibition produced by maximal concentrations of SNAP, suggesting that endogenous PDEs are constitutively active and regulate cGMP production. These results suggest that the NO-cGMP-PKG pathway may be involved in inhibitory control of the neonatal rat bladder.

scholarly journals Nitric oxide inhibits basolateral 10-pS Cl− channels through the cGMP/PKG signaling pathway in the thick ascending limb of C57BL/6 mice

2016 ◽  
Vol 310 (8) ◽  
pp. F755-F762 ◽  
Author(s):  
Peng Wu ◽  
Zhongxiuzi Gao ◽  
Shiwei Ye ◽  
Zhi Qi
Keyword(s):  
Nitric Oxide ◽  
Soluble Guanylyl Cyclase ◽  
Inhibitory Effect ◽  
No Synthase ◽  
Thick Ascending Limb ◽  
Channel Activity ◽  
No Donor ◽  
Cgmp Analog ◽  
Synthase Inhibitor

We used patch-clamp techniques to examine whether nitric oxide (NO) decreases NaCl reabsorption by suppressing basolateral 10-pS Cl− channels in the thick ascending limb (TAL). Both the NO synthase substrate l-arginine (l-Arg) and the NO donor S-nitroso- N-acetylpenicillamine significantly inhibited 10-pS Cl− channel activity in the TAL. The inhibitory effect of l-Arg on Cl− channels was completely abolished in the presence of the NO synthase inhibitor or NO scavenger. Moreover, inhibition of soluble guanylyl cyclase abrogated the effect of l-Arg on Cl− channels, whereas the cGMP analog 8-bromo-cGMP (8-BrcGMP) mimicked the effect of l-Arg and significantly decreased 10-pS Cl− channel activity, indicating that NO inhibits basolateral Cl− channels by increasing cGMP production. Furthermore, treatment of the TAL with a PKG inhibitor blocked the effect of l-Arg and 8-BrcGMP on Cl− channels, respectively. In contrast, a phosphodiesterase 2 inhibitor had no significant effect on l-Arg or 8-BrcGMP-induced inhibition of Cl− channels. Therefore, we conclude that NO decreases basolateral 10-pS Cl− channel activity through a cGMP-dependent PKG pathway, which may contribute to the natriuretic and diuretic effects of NO in vivo.

scholarly journals Role of phosphodiesterase and protein kinase G on nitric oxide-induced inhibition of prolactin release from the rat anterior pituitary

2000 ◽  
pp. 279-284 ◽  
Author(s):  
MO Velardez ◽  
A De Laurentiis ◽  
M del Carmen Diaz ◽  
M Lasaga ◽  
D Pisera ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase ◽  
Anterior Pituitary ◽  
Inhibitory Effect ◽  
Male Rats ◽  
Protein Kinase G ◽  
Camp Concentration ◽  
Prolactin Release ◽  
Pituitary Glands

OBJECTIVE: In order to determine the mechanism by which nitric oxide (NO) inhibits prolactin release, we investigated the participation of cGMP-dependent cAMP-phosphodiesterases (PDEs) and protein kinase G (PKG) in this effect of NO. METHODS: Anterior pituitary glands of male rats were incubated with inhibitors of PDE and PKG with or without sodium nitroprusside (NP). Prolactin release, and cAMP and cGMP concentrations were determined by RIA. RESULTS AND CONCLUSIONS: The inhibitory effect of NP (0.5 mmol/l) on prolactin release and cAMP concentration was blocked by EHNA (10(-4)mol/l) and HL-725 (10(-4)mol/l), inhibitors of cGMP-stimulated cAMP-PDE (PDE2). 8-Br-cGMP (10(-4) and 10(-3)mol/l), which mimics cGMP as a mediator of NP effects on prolactin release, also decreased cAMP concentration. Zaprinast (10(-4)mol/l), a selective inhibitor of specific cGMP-PDE (PDE5), potentiated the NP effect on cAMP concentration. Rp-8-[(4-chlorophenyl)thio]-cGMP triethylamine (Rp-8-cGMP, 10(-7)-10(-6)mol/l), an inhibitor of PKG, reversed the effect of NP on prolactin release. The present study suggests that several mechanisms are involved in the inhibitory effect of NO on prolactin release. The activation of PDE2 by cGMP may mediate the inhibitory effect of NO on cAMP concentration and therefore on prolactin release. NO-activated PKG may also be participating in the inhibitory effect of NO on prolactin release.

Nitric Oxide Activates Leak K+ Currents in the Presumed Cholinergic Neuron of Basal Forebrain

2007 ◽  
Vol 98 (6) ◽  
pp. 3397-3410 ◽  
Author(s):  
Youngnam Kang ◽  
Yoshie Dempo ◽  
Atsuko Ohashi ◽  
Mitsuru Saito ◽  
Hiroki Toyoda ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Basal Forebrain ◽  
Reversal Potential ◽  
Soluble Guanylyl Cyclase ◽  
Outward Current ◽  
Pump Current ◽  
Atp Depletion ◽  
Equilibrium Potential ◽  
No Donor ◽  
Bath Application

Learning and memory are critically dependent on basal forebrain cholinergic (BFC) neuron excitability, which is modulated profoundly by leak K+ channels. Many neuromodulators closing leak K+ channels have been reported, whereas their endogenous opener remained unknown. We here demonstrate that nitric oxide (NO) can be the endogenous opener of leak K+ channels in the presumed BFC neurons. Bath application of 1 mM S-nitroso- N-acetylpenicillamine (SNAP), an NO donor, induced a long-lasting hyperpolarization, which was often interrupted by a transient depolarization. Soluble guanylyl cyclase inhibitors prevented SNAP from inducing hyperpolarization but allowed SNAP to cause depolarization, whereas bath application of 0.2 mM 8-bromoguanosine-3′,5′-cyclomonophosphate (8-Br-cGMP) induced a similar long-lasting hyperpolarization alone. These observations indicate that the SNAP-induced hyperpolarization and depolarization are mediated by the cGMP-dependent and -independent processes, respectively. When examined with the ramp command pulse applied at –70 mV under the voltage-clamp condition, 8-Br-cGMP application induced the outward current that reversed at K+ equilibrium potential ( EK) and displayed Goldman-Hodgkin-Katz rectification, indicating the involvement of voltage-independent K+ current. By contrast, SNAP application in the presumed BFC neurons either dialyzed with the GTP-free internal solution or in the presence of 10 μM Rp-8-bromo-β-phenyl-1,N2-ethenoguanosine 3′,5′-cyclic monophosphorothioate sodium salt, a protein kinase G (PKG) inhibitor, induced the inward current that reversed at potentials much more negative than EK and close to the reversal potential of Na+-K+ pump current. These observations strongly suggest that NO activates leak K+ channels through cGMP-PKG-dependent pathway to markedly decrease the excitability in BFC neurons, while NO simultaneously causes depolarization by the inhibition of Na+-K+ pump through ATP depletion.

scholarly journals Hydrogen Sulfide Increases Nitric Oxide Production and Subsequent S-Nitrosylation in Endothelial Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ping-Ho Chen ◽  
Yaw-Syan Fu ◽  
Yun-Ming Wang ◽  
Kun-Han Yang ◽  
Danny Ling Wang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Hydrogen Sulfide ◽  
Protein Kinase ◽  
Fluorescent Probe ◽  
Acid Methyl Ester ◽  
High Specificity ◽  
Protein S ◽  
No Production ◽  
No Donor

Hydrogen sulfide (H2S) and nitric oxide (NO), two endogenous gaseous molecules in endothelial cells, got increased attention with respect to their protective roles in the cardiovascular system. However, the details of the signaling pathways between H2S and NO in endothelia cells remain unclear. In this study, a treatment with NaHS profoundly increased the expression and the activity of endothelial nitric oxide synthase. Elevated gaseous NO levels were observed by a novel and specific fluorescent probe, 5-amino-2-(6-hydroxy-3-oxo-3H-xanthen-9-yl)benzoic acid methyl ester (FA-OMe), and quantified by flow cytometry. Further study indicated an increase of upstream regulator for eNOS activation, AMP-activated protein kinase (AMPK), and protein kinase B (Akt). By using a biotin switch, the level of NO-mediated protein S-nitrosylation was also enhanced. However, with the addition of the NO donor, NOC-18, the expressions of cystathionine-γ-lyase, cystathionine-β-synthase, and 3-mercaptopyruvate sulfurtransferase were not changed. The level of H2S was also monitored by a new designed fluorescent probe, 4-nitro-7-thiocyanatobenz-2-oxa-1,3-diazole (NBD-SCN) with high specificity. Therefore, NO did not reciprocally increase the expression of H2S-generating enzymes and the H2S level. The present study provides an integrated insight of cellular responses to H2S and NO from protein expression to gaseous molecule generation, which indicates the upstream role of H2S in modulating NO production and protein S-nitrosylation.

scholarly journals Protein Kinase G Phosphorylates Soluble Guanylyl Cyclase on Serine 64 and Inhibits Its Activity

2008 ◽  
Vol 28 (10) ◽  
pp. 1803-1810 ◽  
Author(s):  
Zongmin Zhou ◽  
Nazish Sayed ◽  
Anastasia Pyriochou ◽  
Charis Roussos ◽  
David Fulton ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Guanylyl Cyclase ◽  
Soluble Guanylyl Cyclase ◽  
Protein Kinase G

Maturational changes in the regulation of pulmonary vascular tone by nitric oxide in neonatal rats

2007 ◽  
Vol 293 (5) ◽  
pp. L1261-L1270 ◽  
Author(s):  
Louis G. Chicoine ◽  
Michael L. Paffett ◽  
Mark R. Girton ◽  
Matthew J. Metropoulus ◽  
Mandar S. Joshi ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Guanylyl Cyclase ◽  
Vascular Tone ◽  
Age Groups ◽  
Soluble Guanylyl Cyclase ◽  
No Production ◽  
Sprague Dawley ◽  
No Donor ◽  
Early Postnatal Development ◽  
Old Rats

Nitric oxide (NO) is an important regulator of vasomotor tone in the pulmonary circulation. We tested the hypothesis that the role NO plays in regulating vascular tone changes during early postnatal development. Isolated, perfused lungs from 7- and 14-day-old Sprague-Dawley rats were studied. Baseline total pulmonary vascular resistance (PVR) was not different between age groups. The addition of KCl to the perfusate caused a concentration-dependent increase in PVR that did not differ between age groups. However, the nitric oxide synthase (NOS) inhibitor Nω-nitro-l-arginine augmented the K+-induced increase in PVR in both groups, and the effect was greater in lungs from 14-day-old rats vs. 7-day-old rats. Lung levels of total endothelial, inducible, and neuronal NOS proteins were not different between groups; however, the production rate of exhaled NO was greater in lungs from 14-day-old rats compared with those of 7-day-old rats. Vasodilation to 0.1 μM of the NO donor spermine NONOate was greater in 14-day lungs than in 7-day lungs, and lung levels of both soluble guanylyl cyclase and cGMP were greater at 14 days than at 7 days. Vasodilation to 100 μM of the cGMP analog 8-(4-chlorophenylthio)guanosine-3′,5′-cyclic monophosphate was greater in 7-day lungs than in 14-day lungs. Our results demonstrate that the pulmonary vascular bed depends more on NO production to modulate vascular tone at 14 days than at 7 days of age. The observed differences in NO sensitivity may be due to maturational increases in soluble guanylyl cyclase protein levels.

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