Forebrain circumventricular organs mediate captopril-enhanced ethanol intake in rats.
Chronic peripheral treatments with low doses of the angiotensin-converting enzyme inhibitor, captopril, enhance daily intakes of dilute ethanol solutions in rats as they do the intakes of water and saline solutions. Placing captopril into the drinking water or infusing it SC increases daily intake of 6% (v/v) ethanol from 30-100% over 4-12 days of treatment. The present study examined the effects of electrolytic lesions either of the subfornical organ (SFO) or of the organum vasculosum laminae terminalis (OVLT), on captopril-enhanced ethanol intake. Captopril was infused in minipumps at 5 mg/day for 14 days. The intake of 6% (v/v) ethanol was abolished by SFO lesions and was temporarily reduced by OVLT lesions. The SFO, in particular, is essential for the expression of enhanced ethanol intake during low-dose peripheral captopril administration. Local angiotensin II synthesis and receptor activation at the SFO appear to be the mechanism of the enhanced ethanol drinking during captopril.
Fitts
D A
DA
Department of Psychology, University of Washington, Seattle 98195.
D000428:Alcohol Drinking / Q000503:physiopathology / Q000523:psychology*; D000818:Animals; D002216:Captopril / Q000008:administration & dosage / Q000494:pharmacology*; D004327:Drinking Behavior / Q000502:physiology; D007279:Injections, Subcutaneous; D008297:Male; D011301:Preoptic Area / Q000502:physiology; D016548:Prosencephalon / Q000502:physiology*; D051381:Rats; D013238:Stereotaxic Techniques; D013356:Subfornical Organ / Q000502:physiology
D002216:Captopril