[The role of nitric oxide in deoxycorticosterone acetate-salt hypertensive rats].
The relationship between nitric oxide (NO) and blood pressure (BP) in deoxycorticosterone acetate-salt hypertensive rats (DOC) was investigated. Although urinary NO2- + NO3- (NOx) excretion (UNOxV) increased 2 weeks after surgery (2W-DOC), UNOxV decreased 4 weeks after surgery (4W-DOC) compared with that of the control. BP and UNOxV did not change in DOC after treatment with L-arginine (Arg-DOC). Aorta from 4W-DOC and Arg-DOC had significantly decreased relaxation responses to acetylcholine. Deendothelialized aorta from 4W-DOC and Arg-DOC had significantly decreased relaxation responses to lipopolysaccharide. These data suggest that: 1) transient increase of NO synthesis is accompanied by elevation of BP, but long-term elevation of BP decreases NO synthesis in endothelium and smooth muscle cells; 2) L-arginine supplement has no effect on the development of hypertension nor on NO production by endothelium and smooth muscle cells in DOC.
Ishii
T
T
Department of Cardiology, Surugadai Nihon University Hospital, Tokyo, Japan.
Otsuka
Y
Y
Okabe
T
T
Kanmatsuse
K
K
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000494:pharmacology; D001794:Blood Pressure; D003900:Desoxycorticosterone; D006973:Hypertension / Q000503:physiopathology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D009569:Nitric Oxide / Q000096:biosynthesis / Q000502:physiology*; D051381:Rats; D011921:Rats, Inbred WKY; D014664:Vasodilation / Q000187:drug effects
D008070:Lipopolysaccharides; D009569:Nitric Oxide; D003900:Desoxycorticosterone; D001120:Arginine; D000109:Acetylcholine