EFFECT OF ACUTE ADMINISTRATION OF AN ANGIOTENSIN CONVERTING ENZYME-INHIBITOR, CAPTOPRIL (SQ-14,225), ON EXPERIMENTALLY INDUCED THIRSTS IN RATS

  • 1 January 1980
    • journal article
    • research article
    • Vol. 212  (1) , 53-57
Abstract
To assess the role of angiotensin in the genesis of certain types of thirst, rats were administered the angiotensin converting enzyme inhibitor, captopril, to block the increased H2O intake induced either by H2O deprivation or by i.p. administration of hypertonic saline. H2O deprivation for 24 h resulted in increased H2O intake. Acute administration of captopril 50 mg/kg i.p. at 45 or 60, but not at 15 or 30, min before return of H2O to the dehydrated rats significantly attenuated the drinking response. Rats administered 1% body wt. i.p. of 0.25, 0.50, 0.75 or 1.00 M NaCl solution proportionately increased their H2O intake. Acute administration of captopril 35 mg/kg i.p. 15 min before loading with NaCl solution at any of the above concentrations had no effect on the increased thirst induced. Hypertonic saline-induced thirst is apparently not mediated by angiotensin II receptors while H2O deprivation-induced thirst may involve both osmoreceptors and angiotensin II receptors.