[The effect of exogenous nitric oxide on endothelial dysfunction in two-kidney, one-clip renovascular hypertensive rats].
Previous studies have shown that hypertension causes endothelial dysfunction. To study the influence of exogenous nitric oxide(NO) on endothelial dysfunction produced by hypertension, we administered a non-depressor dose of nipradilol to two-kidney, one-clip renovascular hypertensive rats(2K1C). Sprague-Dawley rats underwent either sham surgery(G-1) or clipping of the left renal artery. From day seven, 2K1C were randomized into 3 groups, placebo treatment(G-2), nipradilol treatment(G-3,) and propranolol treatment(G-4). Urinary NO2- + NO3-(NOx) excretion (UNOx V) was measured 4 weeks after clipping, and then, acetylcholine(Ach), A23187, or sodium nitroprusside(SNP)-induced relaxation were measured in the aorta. Blood pressure was increased in G-2, G-3, and G-4 compared to G-1. UNOx V was lower in G-2, G-3, and G-4 compared to G-1, but UNOx V was higher in G-3 compared to G-2 and G-4. Although Ach or A23187-induced relaxation was significantly decreased in isolated artery from G-2, G-3, and G-4 compared with those from G-1. Ach- or A23187-induced relaxation was improved in G-3. SNP-induced relaxation did not differ among the 4 groups. These results suggest that exogenous NO from nipradilol reduces the endothelial dysfunction caused by hypertension without changing the blood pressure.
Otsuka
Y
Y
Department of Cardiology, Surugadai Nihon University Hospital, Tokyo, Japan.
Harasawa
S
S
Sugiura
H
H
Koike
M
M
Akimoto
H
H
Ishii
T
T
Abeta
H
H
Okabe
T
T
Kushiro
T
T
Kanmatsuse
K
K
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure; D000001:Calcimycin / Q000494:pharmacology; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000503:physiopathology*; D006978:Hypertension, Renovascular / Q000188:drug therapy / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D009569:Nitric Oxide / Q000652:urine; D020030:Nitric Oxide Donors / Q000494:pharmacology* / Q000627:therapeutic use; D011412:Propanolamines / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D014664:Vasodilation / Q000187:drug effects
D020030:Nitric Oxide Donors; D011412:Propanolamines; D009569:Nitric Oxide; D000001:Calcimycin; C036089:nipradilol; D000109:Acetylcholine