Influence of nitric oxide on the cardiovascular action of secretin in intact rats. Part A. Does nitric oxide influence the effect of secretin on arterial blood pressure?
The present study aimed to determine the influence of nitric oxide (NO) on the action of secretin in the cardiovascular system in intact rats. The studies involved the in vivo measurements of the systolic (SBP) and diastolic (DBP) blood pressure. The measurements were conducted when NO was absent, which was attained by the use of NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME), and when NO was in excess which was obtained by the administration of L-arginine (L-arg), the substrate for NO synthase or exogenous donor of NO, sodium nitroprusside (SNP). Secretin given at the following three doses: 0.75, 1.5 and 3.0 micromoles/kg iv increased SBP and DBP. L-NAME inhibited the slight hypertensive effect of secretin. L-arg abolished the hypertensive effect of the peptide given at the smallest dose, did not change the effect of secretin administered at the medium dose (which did not raise the pressure) and preserved the action of the highest secretin dose. SNP abolished the hypertensive effect of all doses of the peptide. In conclusion, the study has shown that both the lack and excess of NO change the in vivo effect of secretin in intact rats.
Sitniewska
E M
EM
Department of Pharmacology, Medical Academy of Białystok, Poland.
Wiśniewska
R J
RJ
Wiśniewski
K
K
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D051381:Rats; D017208:Rats, Wistar; D012633:Secretin / Q000378:metabolism*
D004791:Enzyme Inhibitors; D012633:Secretin; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester