Influence of captopril on fluid and electrolyte balances and adrenocortical responses during sodium deprivation in the rat.
An angiotensin I-converting enzyme inhibitor (captopril) was given by gastric lavage at a dose of 30 mg/kg body weight per day to Long-Evans rats for a 13-day period during which they received a sodium-deficient diet. This regime was preceded by a 3-day period during which measurements were made on the animals on a sodium-replete dietary intake. Control sodium-deprived rats showed increased plasma renin activities, increased peripheral aldosterone concentrations and reduced urinary sodium excretion; they maintained positive sodium balance and the zona glomerulosa of the adrenal cortex hypertrophied. Captopril-treated sodium-deprived rats failed to reduce urinary sodium excretion sufficiently and entered a period of marked and sustained negative sodium balance. Peripheral aldosterone concentrations after 12 days of sodium deprivation in the presence of captopril treatment were similar to those of sodium-replete rats. The adrenocortical zona glomerulosa of the captopril-treated rats did not increase in size and regressive changes were noted.
D000302:Adrenal Cortex / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D002216:Captopril / Q000494:pharmacology*; D004039:Diet, Sodium-Restricted; D008297:Male; D011392:Proline / Q000031:analogs & derivatives*; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000378:metabolism*; D014882:Water-Electrolyte Balance / Q000187:drug effects*
D011392:Proline; D002216:Captopril; D012964:Sodium