Periventricular preoptic-hypothalamic lesions: effects on isoproterenol-induced thirst

Lesions of the periventricular tissue surrounding the anteroventral third ventricle (AV3V) have been shown to block the dipsogenic properties of many experimental manipulations, including injections of angiotensin. The present study examines the ability of rats with ablations of the AV3V to initiate drinking responses following administrations of isoproterenol, a beta-adrenergic agonist which is thought to elicit drinking in part by activating the peripheral renin-angiotensin system. It was found that rats bearing lesions of the AV3V region drank significantly less across a range of doses than animals with sham lesions. When taken together with results from other studies, the present findings suggest that destroying the AV3V region inhibits the thirst-including properties of endogenous, as well as exogenous angiotensin.