Effects of angiotensin on drinking.

A series of four experiments was carried out to assess the effects of angiotensin II on drinking elicited by various types of stimulation. Experimental I examined the effects of the interaction of 2 cc/kg of 5% NaCl plus 0.2 mg/kg angiotensin II on ad lib eating and drinking. Results indicate that NaCl plus angiotensin produced an additive enhancement in water consumption. Experiment 2 was conducted to investigate the effects of 0.2, 0.4, 0.8, 1.2, and 1.6 mg/kg of angiotensin II on drinking and eating in 23 hr water deprived animals. Dose related increases in drinking alone were observed. In Experiment 3 the effects of 0.4, 0.8, 1.2, and 1.6 mg/kg of angiotensin II on schedule dependent lever pressing and schedule induced drinking and licking were determined. Results demonstrate that angiotensin II decreased lever pressing and increased schedule induced water consumption without a concomitant increase in licking. Experimental 4 examined the effects of the same doses of angiotensin II on prandal drinking in food deprived animals. Under these conditions angiotensin II increased water consumption. Results were discussed in terms of the differential effects of angiotensin II on drinking, eating, and schedule dependent lever pressing.