Central administration of a nitric oxide synthase inhibitor causes pressor responses via the sympathetic nervous system and the renin-angiotensin system in Wistar rats.
The central roles of nitric oxide (NO) in regulations of the blood pressure and heart rate were examined in anesthetized rats. Intracerebroventricular (i.c.v.) injection of Nomega-nitro-L-arginine methyl ester (L-NAME) caused dose-dependent increase in the blood pressure and heart rate. The pressor response of the blood pressure to L-NAME (2 micromol, i.c.v.) was reduced by L-arginine (5 micromol, i.c.v). Pretreatment with a ganglionic blocker, pentolinium (10 mg/kg, i.v.), significantly inhibited both pressor responses induced by L-NAME (2 micromol, i.c.v). The later pressor response of the blood pressure to L-NAME was also inhibited by the angiotensin II AT-1 blocker losartan (10 mg/kg, i.v). These results suggest that the response of the blood pressure to L-NAME is mediated by both the sympathetic nervous system and the renin-angiotensin system.
Moriguchi
S
S
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Japan.
Ohzuru
N
N
Koga
N
N
Honda
K
K
Saito
R
R
Takano
Y
Y
Kamiya
H
H
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D007276:Injections, Intraventricular; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000008:administration & dosage; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D052248:Nitric Oxide Synthase Type I; D010425:Pentolinium Tartrate / Q000008:administration & dosage; D051381:Rats; D017208:Rats, Wistar; D012084:Renin-Angiotensin System / Q000187:drug effects* / Q000502:physiology; D013564:Sympathetic Nervous System / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology
D010425:Pentolinium Tartrate; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat; D019331:NG-Nitroarginine Methyl Ester