[Influence of intracerebroventricular injection of sodium nitroprusside L-arginine and NG-nitro-L-arginine on cardiovascular activity in conscious rats].
In order to study the cardiovascular effect of NO in conscious rats, sodium nitroprusside (SNP), the precursor of NO (L-Arginine, Arg-Arg) and one of the inhibitor of NOS (NG-nitro-L-arginine, NNLA) were intracerebroventricularly (icv) injected. Our experimental results indicated that, an apparent dose-dependent hypertensive effect was produced by icv administration of SNP (8, 16, 32 and 32 micrograms), a tachycardiac effect was also produced at the same time. In addition, hypertension and tachycardia were produced by icv L-arginine and the dipeptide Arg-Arg. Furthermore a hypotensive and bradycardiac effect can be produced by icv NNLA. These results suggest that there is a positive effect on cardiovascular activity due to increase of endogeneuse NO in the rat brain and a negative effect on cardiovascular activity due to decrease of endogeneuse NO in the rat brain.
Department of Physiology, Beijing Medical University, Beijing 100083.
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D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D001120:Arginine / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects*; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D007276:Injections, Intraventricular; D008297:Male; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D052248:Nitric Oxide Synthase Type I; D019335:Nitroarginine / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D000959:Antihypertensive Agents; D009599:Nitroprusside; D019335:Nitroarginine; D001120:Arginine; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat