Effect of an angiotensin converting enzyme inhibitor (SQ 14,225) on beta-adrenergic and angiotensin-induced thirsts

• Published in: European journal of pharmacology Vol. 56; no. 1-2; p. 123
• Main Authors: Katovich, M J, Barney, C C, Fregly, M J, McCaa, R E
• Format: Journal Article
• Language: English
• Published: Netherlands 01.06.1979
• Subjects: Angiotensin I - pharmacology; Angiotensin II - pharmacology; Angiotensin-Converting Enzyme Inhibitors; Animals; Drinking - drug effects; Female; Isoproterenol - pharmacology; Proline - analogs & derivatives; Proline - pharmacology; Rats; Thirst - drug effects
• ISSN: 0014-2999
• DOI: 10.1016/0014-2999(79)90441-2

The effect of acute administration of SQ 14,225, a new angiotensin converting enzyme inhibitor, on the drinking response of female rats administered either isoprenaline, angiotensin I, or angiotensin II was studied during 2 h after treatment. Administration of isoprenaline (25 micrograms/kg body wt) was accompanied by a significant increase in water intake when compared with saline-treated controls. Acute administration of a constant dose of isoprenaline (25 micrograms/kg body wt) and increasing doses of SQ 14,225 (5--50 mg/kg) was accompanied by a dose-related, linear decrease in water intake. Acute administration of either angiotensin I or angiotensin II (200 micrograms/kg body wt) was accompanied by a significant increase in water intake. The dipsogenic response to angiotensin II was not affected by acute administration of 35 mg SQ 14,225/kg body wt. However, at the same dose of SQ 14,225, angiotensin I-induced thirst was attenuated. Since isoprenaline-induced and angiotensin I-induced, but not angiotensin II-induced, thirsts are blocked by SQ 14,225, the results suggest that isoprenaline-induced thirst is mediated by way of the renin--angiotensin system.