Influence of sodium diet on L-NAME effects on renin release and renal vasoconstriction.
The intervention of the L-arginine-NO pathway in renal vasodilation and renin secretion was studied in an isolated perfused rat kidney model. NG-nitro-L-arginine methyl ester (L-NAME, 1-25 microM), an inhibitor of nitric oxide (NO) synthesis, caused a dose-dependent increase in perfusion pressure (PP) and a dose-dependent decrease in renal perfusate flow. Renin was inhibited independently of the rise in PP, since the effect of L-NAME on renin release was the same when PP was maintained constant. Exposure of rats to low [salt depleted (SD)] or high [salt repleted (SR)] salt intake for 1 mo influenced the renal vascular response to L-NAME (3 microM). Isolated SR rat kidney vasculature vasoconstricted to a greater extent after inhibition of NO synthase than did that of SD kidneys. A similar fall in renin release was observed after L-NAME in both groups, despite a higher renin secretion rate in SD than in SR rats. These results suggest that NO-dependent vasodilation counteracts the renal vasoconstrictor effect of sodium loading.
Gardes
J
J
Institut National de la Santé et de la Recherche Médicale U367, Paris, France.
Gonzalez
M F
MF
Alhenc-Gelas
F
F
Ménard
J
J
D000704:Analysis of Variance; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004039:Diet, Sodium-Restricted; D004231:Diuresis / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D007668:Kidney / Q000098:blood supply / Q000187:drug effects* / Q000201:enzymology; D007700:Kinetics; D008297:Male; D015999:Multivariate Analysis; D019331:NG-Nitroarginine Methyl Ester; D009318:Natriuresis / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D012039:Regional Blood Flow / Q000187:drug effects; D012079:Renal Circulation / Q000187:drug effects*; D012083:Renin / Q000378:metabolism*; D012982:Sodium, Dietary / Q000494:pharmacology*; D013997:Time Factors; D014661:Vasoconstriction / Q000187:drug effects*
D012982:Sodium, Dietary; D001120:Arginine; D012083:Renin; D019331:NG-Nitroarginine Methyl Ester