Antagonism of the renin-angiotensin system and water deprivation-induced NaCl intake in rats.
Adult male rats (n = 5-7 per group) were water deprived for 24 h with only food available. Then they had access to water for 2 h. At the end of the 2 h, 1.5% NaCl was offered to the animals and the intake was measured for another 2 h. The rats drank an average of 9.8 +/- 3.0 ml/120 min of 1.5% NaCl; water intake during this time was negligible (not more than 1.0 ml/120 min). Captopril injected i.p. at the doses of 12 and 24 mg/ kg induced 60-90% inhibition of the intake. Losartan or PD123319 injected i.c.v. induced 50-80% inhibition of the intake. Losartan (80 nmol) inhibited the intake at a lower dose than PD123319 (160 nmol). Neither losartan nor PD123319 inhibited 10% sucrose intake. The inhibition of 1.5% NaCl intake was not related to alterations in arterial pressure. The results show that the antagonism of the renin-angiotensin system inhibits the 1.5% NaCl intake induced by water deprivation. The inhibition induced by the angiotensin II antagonists suggest that this peptide is important for the control of salt intake induced by water deprivation.
Sato
M A
MA
Department of Physiological Sciences, School of Dentistry, Paulista State University, Säo Paulo, Brazil.
Yada
M M
MM
De Luca
L A
LA
D000818:Animals; D002216:Captopril / Q000494:pharmacology*; D004326:Drinking / Q000187:drug effects*; D008297:Male; D051381:Rats; D012084:Renin-Angiotensin System / Q000502:physiology*; D012965:Sodium Chloride / Q000494:pharmacology; D014868:Water Deprivation / Q000502:physiology*
D012965:Sodium Chloride; D002216:Captopril