ABSTRACT
The RAS may influence alt and water balance through the central nervou system. Both the renal RAS, through the peripheral circulation, and the brrun RAS may be involved. Intravenous infusion of angioten in II (Ang II), which effect blood level of Ang II imilar to those found after hypovoJemja and renal artery tenosi , can stimulate thir t. Although Ang II doe not readily penetrate the blood-brain barrier, the ubfomical organ (SFO) and the vascu lar circumventricular organ have fene trated capillarie that allow circulating Ang II to reach the appropriate neuron . These area are also very en itive to direct injections of Ang 11, which produce striking increa e in drinking behavior. De truction of the SFO re ult in a lo of drinking re pon e to intravenou infusion of Ang II in everal specie (Fitz imon and Simon 1969; Ep tein , Fitz imon and Roll , 1970). Another ite in the brrun, the preoptic area, al o elicit drinking behavior when timulated by intraventricular injection of Ang U (Fitz imon and Kucharczyk, 1978).
