Angiotensin and drinking rates in the euryhaline killifish.

Drinking rates were measured in the euryhaline fish Fundulus heteroclitus in the presence and absence of angiotensin II or its competitive inhibitor P-113 and converting enzyme inhibitor (SQ20881). Angiotensin stimulated drinking in Fundalus adapted to salt- or freshwater. More significant, P-113 decreased drinking rates in saltwater-adapted fish and to ones acutely exposed to saltwater. SQ20881 was also effective in inhibiting drinking. These data are interpreted to support the hypothesis that endogenously produced angiotensin is a physiological stimulus for drinking in fish.