A NITRIC OXIDE DONOR (SPERMINE-NONOATE) PREVENTS THE FORMATION OF NEOINTIMA IN RABBIT CAROTID ARTERY

1997 ◽  
Vol 24 (6) ◽  
pp. 436-438 ◽  
Author(s):  
ZL Yin ◽  
GJ Dusting
Keyword(s):  
Nitric Oxide ◽  
Carotid Artery ◽  
Nitric Oxide Donor ◽  
Rabbit Carotid Artery ◽  
Spermine Nonoate

Nitric oxide attenuates endothelin-1-induced vasoconstriction in canine stomach

1996 ◽  
Vol 271 (1) ◽  
pp. G27-G35
Author(s):  
J. G. Wood ◽  
Q. Zhang ◽  
Z. Y. Yan ◽  
L. Y. Cheung
Keyword(s):  
Nitric Oxide ◽  
Methyl Ester ◽  
Ischemia Reperfusion ◽  
Nitric Oxide Donor ◽  
Question Mark ◽  
Endothelin 1 ◽  
Vasoconstrictor Response ◽  
Anesthetized Dogs ◽  
Spermine Nonoate

We previously observed that endothelin-1 (ET-1)-induced gastric vasoconstriction is enhanced after ischemia-reperfusion. The purpose of our present study was to examine the role of nitric oxide in regulating ET-1-induced vasoconstriction under normal conditions and after ischemia-reperfusion. Using a mechanically perfused stomach segment from chloralose-anesthetized dogs, we examined 1) responses to NG-nitro-L-arginine methyl ester (L-NAME) alone and in combination with L-arginine, 2) whether L-NAME affects ET-1-induced vasoconstriction under normal conditions and after ischemia-reperfusion, and 3) if spermine NONOate inverted question mark1,3-propanediamine-N-[4-1-(3-aminopropyl)-2-hydroxy-2-nitrosohydrazi no] butyl; a nitric oxide donor inverted question mark attenuates the augmented response to ET-1 after ischemia-reperfusion. Our results show that 1) L-NAME significantly increased baseline vascular resistance and this response was reduced by L-arginine, 2) ET-1-induced vasoconstriction was enhanced by L-NAME, and 3) administration of spermine NONOate during reperfusion largely attenuated the vasoconstrictor response to ET-1 after ischemia-reperfusion. Our findings are consistent with the hypothesis that nitric oxide modulates responses to ET-1 under normal conditions, and loss of this vasodilator after ischemia-reperfusion results in an augmented response to ET-1.

Lovastatin maintains nitric oxide—but not EDHF-mediated endothelium-dependent relaxation in the hypercholesterolemic rabbit carotid artery

1999 ◽  
Vol 142 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Ralf P. Brandes ◽  
Andreas Behra ◽  
Corinna Lebherz ◽  
Rainer H. Böger ◽  
Stefanie M. Bode-Böger ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Carotid Artery ◽  
Rabbit Carotid Artery ◽  
Endothelium Dependent Relaxation

Evidence that nitric oxide synthase is involved in progesterone-induced acrosomal exocytosis in mouse spermatozoa

1997 ◽  
Vol 9 (4) ◽  
pp. 433 ◽  
Author(s):  
María Beléen Herrero ◽  
J. Marcelo Viggiano ◽  
Silvina Pérez Martínez ◽  
Martha F. de Gimeno
Keyword(s):  
Nitric Oxide ◽  
Methyl Ester ◽  
Nitric Oxide Synthase ◽  
No Synthase ◽  
Nitric Oxide Donor ◽  
Mouse Sperm ◽  
Acrosomal Exocytosis ◽  
Oxide Synthase ◽  
Spermine Nonoate

In a recent work, we detected nitric oxide synthase (NO synthase) in the acrosome and tail of mouse and human spermatozoa by an immunofluorescence technique. Also, NO-synthase inhibitors added during sperm capacitationin vitro reduced the percentage of oocytes fertilized in vitro, suggesting a role for NO synthase in sperm function. Therefore, in the present study the effect of three NO-synthase inhibitors, NG-nitro-L-arginine methyl ester (L-NAME), NG-nitro-D-arginine methyl ester (D-NAME) and L-NG-nitro-arginine (NO2-arg), and of a nitric oxide donor, spermine-NONOate, on the progesterone-induced acrosome reaction of mouse sperm was examined. NO-synthase inhibitors were added at 0, 60 or 90 min during capacitation; at 120 min, mouse epididymal spermatozoa were exposed to 15 µM progesterone for another 15 min. In another set of experiments, different concentrations of spermine-NONOate were added to capacitated spermatozoa for 15 min; in these experiments, progesterone was not included. NO2-arg and L-NAME blocked progesterone-induced exocytosis regardless of the time at which these inhibitors were added. Moreover, D-NAME did not inhibit exocytosis. In contrast, spermine-NONOate stimulated the acrosomal exocytosis in vitro directly. These results provide evidence that mouse sperm NO synthase participates in the progesterone-induced acrosome reactionin vitro and that nitric oxide induces this event.

Enhanced role of potassium channels in relaxations to acetylcholine in hypercholesterolemic rabbit carotid artery

1994 ◽  
Vol 266 (5) ◽  
pp. H2061-H2067 ◽  
Author(s):  
S. Najibi ◽  
C. L. Cowan ◽  
J. J. Palacino ◽  
R. A. Cohen
Keyword(s):  
Nitric Oxide ◽  
Methyl Ester ◽  
Carotid Artery ◽  
Potassium Channels ◽  
Abdominal Aorta ◽  
Combined Treatment ◽  
Rabbit Carotid Artery ◽  
Calcium Dependent ◽  
Endothelium Dependent Relaxation

The effect of hypercholesterolemia for 10 wk on endothelium-dependent relaxations to acetylcholine was studied in isolated rings of rabbit carotid artery and abdominal aorta contracted with phenylephrine or elevated potassium. In these arteries obtained from hypercholesterolemic rabbits, endothelium-dependent relaxations to acetylcholine were not significantly different from those of normal rabbits. In normal and hypercholesterolemic arteries, partial relaxation persisted in the presence of NG-nitro-L-arginine methyl ester (L-NAME), which blocked acetylcholine-induced increases in arterial guanosine 3',5'-cyclic monophosphate (cGMP). Combined treatment with L-NAME and the calcium-dependent potassium-channel inhibitor, charybdotoxin, blocked relaxations in both groups, suggesting that L-NAME-resistant relaxations are mediated by an endothelium-derived hyperpolarizing factor. Charybdotoxin alone or depolarizing potassium had no significant effect on normal carotid artery or normal and hypercholesterolemic abdominal aorta but significantly inhibited relaxations of the carotid artery from cholesterol-fed rabbits. The enhanced role of calcium-dependent potassium channels and the hyperpolarizing factor in relaxation of the hypercholesterolemic carotid artery suggested by these results was likely related to the fact that acetylcholine failed to stimulate cGMP only in that artery. These data suggest that endothelium-dependent relaxation in these rabbit arteries is mediated by nitric oxide-cGMP-dependent and -independent mechanisms. In hypercholesterolemia, the contribution of nitric oxide-cGMP in the carotid artery is reduced, but a hyperpolarizing factor and calcium-dependent potassium channels maintain normal acetylcholine-induced relaxation.

Guanylyl cyclase stimulatory coupling to KCachannels

2000 ◽  
Vol 279 (6) ◽  
pp. C1938-C1945 ◽  
Author(s):  
M. Nara ◽  
P. D. K. Dhulipala ◽  
G. J. Ji ◽  
U. R. Kamasani ◽  
Y.-X. Wang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase ◽  
Guanylyl Cyclase ◽  
Phosphorylation Site ◽  
Nitric Oxide Donor ◽  
Dependent Manner ◽  
Dependent Protein Kinase ◽  
Α Subunit ◽  
Dependent Protein ◽  
Spermine Nonoate

We coexpressed the human large-conductance, calcium-activated K (KCa) channel (α- and β-subunits) and rat atrial natriuretic peptide (ANP) receptor genes in Xenopus oocytes to examine the mechanism of guanylyl cyclase stimulatory coupling to the channel. Exposure of oocytes to ANP stimulated whole cell KCa currents by 21 ± 3% (at 60 mV), without altering current kinetics. Similarly, spermine NONOate, a nitric oxide donor, increased KCa currents (20 ± 4% at 60 mV) in oocytes expressing the channel subunits alone. Stimulation of KCacurrents by ANP was inhibited in a concentration-dependent manner by a peptide inhibitor of cGMP-dependent protein kinase (PKG). Receptor/channel stimulatory coupling was not completely abolished by mutating the cAMP-dependent protein kinase phosphorylation site on the α-subunit (S869; Nars M, Dhulipals PD, Wang YX, and Kotlikoff MI. J Biol Chem 273: 14920–14924, 1998) or by mutating a neighboring consensus PKG site (S855), but mutation of both residues virtually abolished coupling. Spermine NONOate also failed to stimulate channels expressed from the double mutant cRNAs. These data indicate that nitric oxide donors stimulate KCa channels through cGMP-dependent phosphorylation and that two serine residues (855 and 869) underlie this stimulatory coupling.

Inhalation Anesthetics Inhibit the Release of Endothelium-derived Hyperpolarizing Factor in the Rabbit Carotid Artery

1995 ◽  
Vol 83 (3) ◽  
pp. 574-582. ◽  
Author(s):  
Volker Lischke ◽  
Rudi Busse ◽  
Markus Hecker
Keyword(s):  
Nitric Oxide ◽  
Cytochrome P450 ◽  
Carotid Artery ◽  
Sodium Nitroprusside ◽  
Liver Microsomes ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Inhalation Anesthetics ◽  
Rabbit Carotid Artery ◽  
Relaxant Response

Background Inhalation anesthetics may interfere with the synthesis or action of endothelium-derived vasoactive factors. We investigated the effects of desflurane, enflurane, halothane, isoflurane, and sevoflurane on the release of nitric oxide and endothelium-derived hyperpolarizing factor (EDHF) in the isolated endothelium-intact carotid artery of the rabbit. Methods Isolated segments of the carotid artery were suspended in Krebs-Henseleit solution (37 degrees C) and preconstricted with phenylephrine (1 microM). Relaxations caused by acetylcholine (ACh) (0.03-10 microM) or sodium nitroprusside (0.01-10 microM) were compared in the presence or absence of the nitric oxide synthase inhibitor NG-nitro-L-arginine (0.1 mM) in segments exposed to desflurane (8%), enflurane (2-4%), halothane (2-3.5%), isoflurane (2-4%), or sevoflurane (2%) as well as in NG-nitro-L- arginine-treated segments exposed to enflurane (2%) in combination with the KCa(+)-channel blocker tetrabutylammonium (0.3 mM) or the cytochrome P450 inhibitor clotrimazole (3 microM). Results Desflurane, enflurane, and sevoflurane selectively inhibited the ACh-induced release of EDHF. Halothane and isoflurane also weakly affected the nitric oxide-mediated relaxant response to ACh. The inhibitory effect of these two anesthetics on EDHF release was concentration-dependent. Relaxations induced by sodium nitroprusside were not inhibited by any of the anesthetics tested. Three structurally unrelated cytochrome P450 inhibitors clotrimazole (0.1 mM), metyrapone (1 mM), and SKF525a (proadifen, 0.1 mM) abolished the EDHF-mediated relaxation elicited by ACh. The pharmacologic profile of the inhibitory effect of enflurane on the release of EDHF closely resembled that of clotrimazole but not that of tetrabutylammonium. Moreover, all anesthetics inhibited the cytochrome P450-catalyzed O-dealkylation of 7-ethoxycoumarin by rabbit liver microsomes in a concentration-dependent manner. Conclusions Inhalation anesthetics significantly attenuate the EDHF-mediated relaxant response to ACh in the rabbit carotid artery. This effect appears to be attributable to inhibition of the cytochrome P450-dependent synthesis of EDHF by the endothelium.

Sign in / Sign up

Export Citation Format

Share Document