Effect of aging on nitric oxide-mediated penile erection in rats

1995 ◽  
Vol 268 (1) ◽  
pp. H467-H475 ◽  
Author(s):  
H. Garban ◽  
D. Vernet ◽  
A. Freedman ◽  
J. Rajfer ◽  
N. Gonzalez-Cadavid
Keyword(s):  
Nitric Oxide ◽  
Muscle Relaxation ◽  
Phosphodiesterase Inhibitor ◽  
Smooth Muscle Relaxation ◽  
Adult Rats ◽  
No Donor ◽  
Tissue Sections ◽  
Old Rats ◽  
Nos Inhibitor ◽  
Erectile Response

Aging is an important risk factor for impotence in men. Because nitric oxide (NO) appears to be the mediator of corpora cavernosal smooth muscle relaxation, we have examined in 5-, 20-, and 30-mo-old rats, designated “adult,” “old,” and “senescent,” respectively, whether aging causes a decrease of erectile response that may correlate with lower NO synthase (NOS) in the penis. Electric field stimulation (EFS) of the cavernosal nerve showed that the maximum intracavernosal pressure (MIP) declined in the old and senescent rats to 80 and 51% of the adult value, respectively. A low systemic dose of the NOS inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME; 2 mg/kg), reduced the MIP by only 38% in the adult rats but decreased it in the old and senescent rats by 72 and 80%, respectively. In the absence of EFS, intracavernosal papaverine (phosphodiesterase inhibitor), or nitroglycerin (NO donor), caused a lower erectile response in the old and senescent rats compared with the adult animals (MIP: 41 and 14%, respectively; duration of the erection 46 and 21%, respectively). Tissue sections from old and senescent penises showed increasing degrees of sclerotic degeneration. In comparison with the adult rats, the penile soluble NOS activity per gram of tissue that is sensitive to L-NAME decreased significantly by 63% in the senescent rats but was elevated in the old rats. These results indicate that aging causes an erectile failure due to factors initially independent from an impairment of penile NO synthesis but which are compounded in the very old rats by the decrease of penile NOS activity.

SIN-1 reverses attenuation of hypercapnic cerebrovasodilation by nitric oxide synthase inhibitors

1994 ◽  
Vol 267 (1) ◽  
pp. R228-R235 ◽  
Author(s):  
C. Iadecola ◽  
F. Zhang ◽  
X. Xu
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Muscle Relaxation ◽  
Smooth Muscle Relaxation ◽  
Co2 Response ◽  
No Donor ◽  
No Donors ◽  
Doppler Probe ◽  
Nos Inhibitor ◽  
Oxide Synthase

We sought to determine whether the attenuation of the hypercapnic cerebrovasodilation associated with inhibition of nitric oxide synthase (NOS) can be reversed by exogenous NO. Rats were anesthetized (halothane) and ventilated. Neocortical cerebral blood flow (CBF) was monitored by a laser-Doppler probe. The NOS inhibitor N omega-nitro-L-arginine methyl ester (L-NAME; 40 mg/kg iv) reduced resting CBF [-36 +/- 5% (SE); P < 0.01, analysis of variance] and attenuated the increase in CBF elicited by hypercapnia (partial pressure of CO2 = 50-60 mmHg) by 66% (P < 0.01). L-NAME reduced forebrain NOS catalytic activity by 64 +/- 3% (n = 10; P < 0.001). After L-NAME, intracarotid infusion of the NO donor 3-morpholinosydnonimine (SIN-1; n = 6) increased resting CBF and reestablished the CBF increase elicited by hypercapnia (P > 0.05 from before L-NAME). Similarly, infusion of the guanosine 3',5'-cyclic monophosphate (cGMP) analogue 8-bromo-cGMP (n = 6) reversed the L-NAME-induced attenuation of the hypercapnic cerebrovasodilation. The NO-independent vasodilator papaverine (n = 6) increased resting CBF but did not reverse the attenuation of the CO2 response. SIN-1 did not affect the attenuation of the CO2 response induced by indomethacin (n = 6). The observation that NO donors reverse the L-NAME-induced attenuation of the CO2 response suggests that a basal level of NO is required for the vasodilation to occur. The findings are consistent with the hypothesis that NO is not the final mediator of smooth muscle relaxation in hypercapnia.(ABSTRACT TRUNCATED AT 250 WORDS)

Endothelin-1-induced vasoconstriction is inhibited during erection in rats

2001 ◽  
Vol 281 (2) ◽  
pp. R476-R483 ◽  
Author(s):  
T. M. Mills ◽  
D. M. Pollock ◽  
R. W. Lewis ◽  
H. S. Branam ◽  
C. J. Wingard
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Muscle Relaxation ◽  
Corpus Cavernosum ◽  
Smooth Muscle Relaxation ◽  
No Donor ◽  
Intracavernosal Injection ◽  
Endothelin 1

Recent evidence indicates that endothelin-1 (ET-1) might be a principal vasoconstrictor in the penis. We report that ET-1 injection into the cavernous sinuses before erection sharply reduced the magnitude of subsequent erections. Corpus cavernosum pressure-to-mean arterial pressure ratios (CCP/MAP), with maximal ganglionic stimulation, were 0.62 ± 0.05 before ET-1 injection and 0.31 ± 0.05 after, indicating that ET-1 acted as a vasoconstrictor. When ET-1 was injected during a maximal neurally induced erection, the ability of ET-1 to attenuate subsequent erections was diminished (CCP/MAP 0.75 ± 0.02 before ET-1, 0.61 ± 0.03 after). At submaximal stimulation voltages, injection of ET-1 during erection also attenuated its vasoconstrictive effect. Similarly, when ET-1 was injected during erection induced by intracavernosal injection of the nitric oxide (NO) donor NOR-1, subsequent erections were not significantly suppressed (CCP/MAP 0.53 ± 0.04 before ET-1, 0.45 ± 0.04 after). These findings that ET-1-induced vasoconstriction is attenuated during erection are consistent with the hypothesis that NO mediates erection both by initiating pathways that cause smooth muscle relaxation and by inhibiting the vasoconstrictive actions of ET-1.

Nitric oxide and cGMP: mediators of pelvic nerve-stimulated erection in dogs

1993 ◽  
Vol 264 (2) ◽  
pp. H419-H422 ◽  
Author(s):  
F. Trigo-Rocha ◽  
W. J. Aronson ◽  
M. Hohenfellner ◽  
L. J. Ignarro ◽  
J. Rajfer ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Muscle Relaxation ◽  
Specific Inhibitor ◽  
Phosphodiesterase Inhibitor ◽  
Smooth Muscle Relaxation ◽  
Pelvic Nerve ◽  
Intracavernous Injection ◽  
Penile Tumescence

We sought to determine whether the L-arginine-nitric oxide-guanosine 3',5'-cyclic monophosphate (cGMP) pathway, known to mediate neurostimulation-induced smooth muscle relaxation in penile tissue of rabbits and humans in vitro, is operative also in vivo. Adult male dogs (n = 9) were subjected to direct electrical stimulation of the pelvic nerves to induce penile tumescence. Intracavernous injection of the nitric oxide-releasing substance S-nitroso-N-acetylpenicillamine resulted in similar tumescence. Intracavernous injection of a specific inhibitor of nitric oxide synthesis, NG-nitro-L-arginine, blocked pelvic nerve-stimulated tumescence, and this was partially reversed by intracavernous injection of the nitric oxide precursor L-arginine. Furthermore, neurostimulated tumescence was inhibited by methylene blue, an inhibitor of cytosolic guanylate cyclase and enhanced by M&B 22948, a cGMP phosphodiesterase inhibitor. These in vivo findings support the hypothesis that cavernous smooth muscle relaxation and penile tumescence are mediated by nitric oxide and cGMP.

scholarly journals Augmentation of cGMP/PKG pathway and colonic motility by hydrogen sulfide

2017 ◽  
Vol 313 (4) ◽  
pp. G330-G341 ◽  
Author(s):  
Ancy D. Nalli ◽  
Sayak Bhattacharya ◽  
Hongxia Wang ◽  
Derek M. Kendig ◽  
John R. Grider ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Hydrogen Sulfide ◽  
Muscle Relaxation ◽  
Colonic Motility ◽  
Soluble Guanylyl Cyclase ◽  
Colonic Transit ◽  
Smooth Muscle Relaxation ◽  
No Donor ◽  
Phosphodiesterase 5

Hydrogen sulfide (H2S), like nitric oxide (NO), causes smooth muscle relaxation, but unlike NO, does not stimulate soluble guanylyl cyclase (sGC) activity and generate cyclic guanosine 5′-monophosphate (cGMP). The aim of this study was to investigate the interplay between NO and H2S in colonic smooth muscle. In colonic smooth muscle from rabbit, mouse, and human, l-cysteine, substrate of cystathionine-γ-lyase (CSE), or NaHS, an H2S donor, inhibited phosphodiesterase 5 (PDE5) activity and augmented the increase in cGMP levels, IP3 receptor phosphorylation at Ser1756 (measured as a proxy for PKG activation), and muscle relaxation in response to NO donor S-nitrosoglutathione (GSNO), suggesting augmentation of cGMP/PKG pathway by H2S. The inhibitory effect of l-cysteine, but not NaHS, on PDE5 activity was blocked in cells transfected with CSE siRNA or treated with CSE inhibitor d,l-propargylglycine (dl-PPG), suggesting activation of CSE and generation of H2S in response to l-cysteine. H2S levels were increased in response to l-cysteine, and the effect of l-cysteine was augmented by GSNO in a cGMP-dependent protein kinase-sensitive manner, suggesting augmentation of CSE/H2S by cGMP/PKG pathway. As a result, GSNO-induced relaxation was inhibited by dl-PPG. In flat-sheet preparation of colon, l-cysteine augmented calcitonin gene-related peptide release in response to mucosal stimulation, and in intact segments, l-cysteine increased the velocity of pellet propulsion. These results demonstrate that in colonic smooth muscle, there is a novel interplay between NO and H2S. NO generates H2S via cGMP/PKG pathway, and H2S, in turn, inhibits PDE5 activity and augments NO-induced cGMP levels. In the intact colon, H2S promotes colonic transit. NEW & NOTEWORTHY Hydrogen sulfide (H2S) and nitric oxide (NO) are important regulators of gastrointestinal motility. The studies herein provide the cross talk between NO and H2S signaling to mediate smooth muscle relaxation and colonic transit. H2S inhibits phosphodiesterase 5 activity to augment cGMP levels in response to NO, which, in turn, via cGMP/PKG pathway, generates H2S. These studies suggest that interventions targeted at restoring NO and H2S homeostasis within the smooth muscle may provide novel therapeutic approaches to mitigate motility disorders.

Transdermal Nitroglycerine in the Management of Pain Associated with Primary Dysmenorrhoea: A Multinational Pilot Study

1997 ◽  
Vol 25 (1) ◽  
pp. 41-44 ◽  
Author(s):  
O Ré ◽  
Keyword(s):  
Nitric Oxide ◽  
Pain Relief ◽  
Muscle Relaxation ◽  
Nitric Oxide Donor ◽  
Controlled Study ◽  
Smooth Muscle Relaxation ◽  
Uterine Contractility ◽  
Double Blind ◽  
Patch Application ◽  
Endogenous Nitric Oxide

Endogenous nitric oxide mediates smooth-muscle relaxation with subsequent vasodilatation in the vascular, pulmonary, gastrointestinal and genitourinary tissues. Transdermal nitroglycerine (a nitric oxide donor) has been found effective in inhibiting uterine contractility during premature labour. Sixty-five women with histories of moderate-to-severe pain associated with menses were treated with nitroglycerine patches that delivered 0.2 or 0.1 mg/h. Patches were applied as necessary during the first 3 days of the menstrual cycle for up to three consecutive cycles. Pain intensity was assessed at baseline and at 30 min and at 1, 2 and 4 h after patch application. Most patients obtained pain relief with the first dose of the first day. Pain relief was satisfactory to excellent in 90% of the patients. Headache was reported by 20% of the patients, most often in patients using two consecutive patches. A randomized, double-blind, placebo-controlled study is underway in an attempt to confirm the above findings.

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.

Influence of Nitric Oxide on the Secretory Function of the Bovine Corpus Luteum: Dependence on Cell Composition and Cell-to-Cell Communication

2003 ◽  
Vol 228 (6) ◽  
pp. 741-748 ◽  
Author(s):  
Jerzy J. Jaroszewski ◽  
Dariusz J. Skarzynski ◽  
Robert M. Blair ◽  
William Hansel
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Corpus Luteum ◽  
Cell Contact ◽  
Secretory Function ◽  
No Donor ◽  
Luteal Cells ◽  
Cell Composition ◽  
Bovine Corpus Luteum ◽  
Nos Inhibitor

The objective of the present study was to investigate the role of cell-to-cell contact in the influence of nitric oxide (NO) on the secretory function of the bovine corpus luteum (CL). In Experiment 1, separate small luteal cells (SLC) or large (LLC) luteal cells were perfused with 100 μ M spermineNONOate, a NO donor, or with 100 μ M Nω-nitro-L-arginine methyl ester (L-NAME), a NO synthase (NOS) inhibitor; in Experiment 2, a mixture of LLC and SLC and endothelial cells was cultured and incubated with spermineNONOate or L-NAME; in Experiment 3, spermineNONOate was perfused into the CL (100 mg/4 hr) by a microdialysis system in vivo. Perfusion of isolated SLC and LLC with the NO donor or NOS inhibitor (Experiment 1) did not affect ( P > 0.05) secretion of progesterone (P4) or oxytocin (OT). L-NAME perfusion increased ( P < 0.05) leukotriene C4 (LTC4) secretion by both SLC and LLC cells. Treatment of mixtures of luteal cells with an NO donor (Experiment 2) significantly decreased ( P < 0.001) secretion of P4 and OT and increased ( P < 0.001) production of prostaglandin F2α (PGF2α) and LTC4. L-NAME stimulated ( P < 0.001) P4 secretion, but did not influence ( P > 0.05) OT, PGF2α or LTC4 production. Intraluteal administration (Experiment 3) of spermineNONOate increased ( P < 0.001) LTC4 and PGF2α, decreased OT, but did not change P4 levels in perfusate samples. These data indicate that cell-to-cell contact and cell composition play important roles in the response of bovine CL to treatment with NO donors or NOS inhibitors, and that paracrine mechanisms are required for the full secretory response of the CL in NO action. Endothelial cells appear to be required for the full secretory response of the CL to NO.

Increased nitric oxide availability worsens the cardiac performance during early re-perfusion period in adult rats

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Faten M.A. Diab ◽  
Mahmoud H. Ayobe ◽  
Mohamed F. Abdel-Salam ◽  
Mohammed F.S. Otman ◽  
Enas A. Abdel-Hady
Keyword(s):  
Nitric Oxide ◽  
Flow Rate ◽  
Cardiac Performance ◽  
Control Group ◽  
Adult Rats ◽  
Significant Deterioration ◽  
No Donor ◽  
Langendorff Preparation ◽  
Perfusion Period ◽  
Myocardial Flow

Abstract Objectives Re-perfusion is the standard therapy for acute myocardial infarction, despite the associated pathologies that may contribute to irreversible myocardial injury. The present study aims to clarify the alterations in cardiac activities in response to experimental cardiac ischemic arrest followed by re-perfusion in isolated hearts perfused with nitric oxide (NO) donor, l-arginine, or NO inhibitor, Nω-Nitro-l-arginine methyl ester hydrochloride (l-NAME), to shed light on the possible role of NO in the re-perfusion process. Methods Hearts isolated from adult Wistar rats were studied on Langendorff preparation under basal conditions and during 30 min re-perfusion following 30 min of total global ischemia. Rats were randomly divided into three groups; control and l-arginine or l-NAME infused heart groups. Cardiac tissue content of malondialdhyde, catalase and nitrite was also measured. Results Compared to the control group, both l-arginine and l-NAME infused hearts showed increased basal chronotropy and myocardial flow rate. Following ischemia and during the whole period of re-perfusion, the three groups demonstrated significant deterioration in the inotropic activity and compromised myocardial flow rate. l-arginine infused hearts revealed depressed inotropy and chronotropy, weak systolic and diastolic functions with compromised myocardial flow at early 5 min of re-perfusion, yet with significantly higher myocardial flow rate by the end of re-perfusion. Conclusions Reducing NO availability by l-NAME revealed mild impact on the ischemia re-perfusion induced contractile dysfunction, whereas excess NO worsens cardiac performance at the early re-perfusion period.

Permissive and obligatory roles of NO in cerebrovascular responses to hypercapnia and acetylcholine

1996 ◽  
Vol 271 (4) ◽  
pp. R990-R1001 ◽  
Author(s):  
C. Iadecola ◽  
F. Zhang
Keyword(s):  
Basal Forebrain ◽  
Muscle Relaxation ◽  
Smooth Muscle Relaxation ◽  
Doppler Flowmetry ◽  
No Donors ◽  
Nos Inhibitors ◽  
Fusion Site ◽  
Nos Inhibitor ◽  
Hypercapnic Response ◽  
Major Mediator

Inhibition of nitric oxide (NO) synthesis attenuates the hypercapnic cerebrovasodilation or the increases in cerebral blood flow (CBF) produced by acetylcholine (ACh), either topically applied or endogenously released in neocortex by stimulation of the basal forebrain cholinergic system. We investigated whether exogenous administration of NO, using NO donors, can reverse the attenuation of these responses by NO synthase (NOS) inhibitors. In halothane-anesthetized, ventilated rats the frontoparietal cortex was exposed and superfused with Ringer. CBF was monitored at the super fusion site by laser-Doppler flowmetry. The basal forebrain was stimulated (100 microA; 50 Hz) with microelectrodes stereotaxically implanted. Superfusion with the NOS inhibitor NG-nitro-L-arginine (L-NNA; 1 mM) reduced resting CBF (-38 +/- 2%; mean +/- SE) and attenuated the vasodilation elicited by hypercapnia (Pco2, 50-60 mmHg; -79 +/- 3%), ACh (10 microM; -83 +/- 7%), or basal forebrain stimulation (-44 +/- 2%) (P < 0.05, analysis of variance and Tukey's test). After L-NNA, topical application of 3-morpholinosydnonimine (SIN-1) (n = 7), S-nitroso-N-acetylpenicillamine (SNAP) (n = 6), or 8-bromoguanosine 3',5'-monophosphate (8-BrcGMP, n = 4) reestablished resting CBF (P > 0.05 from Ringer) and reversed the attenuation of the response to hypercapnia (P > 0.05 from Ringer). However, SIN-1 or SNAP failed to reverse the attenuation of the response to basal forebrain stimulation or topical ACh (P > 0.05 from L-NNA). After L-NNA, the NO-independent vasodilator papaverine (n = 4) reestablished resting CBF (P > 0.05 from Ringer) but failed to restore the hypercapnic vasodilation (P > 0.05 from L-NNA). The attenuation of hypercapnic response by the neuronal NOS inhibitor 7-nitroindazole was counteracted only partially by SIN-1 (n = 4) or 8-BrcGMP (n = 4). The data support the hypothesis that the vasodilation elicited by hypercapnia requires resting levels of NO for its expression, whereas the response to endogenous or exogenous ACh depends on agonist-induced NOS activation. In hypercapnia NO may act as a permissive factor by facilitating the action of other vasodilators, whereas in the vascular response initiated by ACh NO is likely to be the major mediator of smooth muscle relaxation.

scholarly journals A theoretical model of nitric oxide transport in arterioles: frequency- vs. amplitude-dependent control of cGMP formation

2004 ◽  
Vol 286 (3) ◽  
pp. H1043-H1056 ◽  
Author(s):  
Nikolaos M. Tsoukias ◽  
Mahendra Kavdia ◽  
Aleksander S. Popel
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Smooth Muscle ◽  
Soluble Guanylate Cyclase ◽  
Muscle Tone ◽  
Muscle Relaxation ◽  
Smooth Muscle Relaxation ◽  
No Production ◽  
Cgmp Formation

Nitric oxide (NO) plays many important physiological roles, including the regulation of vascular smooth muscle tone. In response to hemodynamic or agonist stimuli, endothelial cells produce NO, which can diffuse to smooth muscle where it activates soluble guanylate cyclase (sGC), leading to cGMP formation and smooth muscle relaxation. The close proximity of red blood cells suggests, however, that a significant amount of NO released will be scavenged by blood, and thus the issue of bioavailability of endothelium-derived NO to smooth muscle has been investigated experimentally and theoretically. We formulated a mathematical model for NO transport in an arteriole to test the hypothesis that transient, burst-like NO production can facilitate efficient NO delivery to smooth muscle and reduce NO scavenging by blood. The model simulations predict that 1) the endothelium can maintain a physiologically significant amount of NO in smooth muscle despite the presence of NO scavengers such as hemoglobin and myoglobin; 2) under certain conditions, transient NO release presents a more efficient way for activating sGC and it can increase cGMP formation severalfold; and 3) frequency-rather than amplitude-dependent control of cGMP formation is possible. This suggests that it is the frequency of NO bursts and perhaps the frequency of Ca2+ oscillations in endothelial cells that may limit cGMP formation and regulate vascular tone. The proposed hypothesis suggests a new functional role for Ca2+ oscillations in endothelial cells. Further experimentation is needed to test whether and under what conditions in silico predictions occur in vivo.

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