Angiotensin and salt appetite: Physiological amounts of angiotensin given peripherally increase salt appetite in the rat.

Two experiments were conducted in which adrenalectomized male Sprague-Dawley rats were maintained ad lib on distilled water, 3% saline, and sodium-free food. In Experiment 1, 45 rats were given 100, 200, 400, 800, and 1,000 micrograms/kg/day desoxycorticosterone acetate (DOCA) im for 5 days to determine the dose of DOCA that would produce the lowest voluntary saline intake, and 800 micrograms/kg/day was found to produce the nadir in saline intake. In Experiment 2, 40 rats were placed ad lib on distilled water, saline, and sodium-free food as described above, maintained on 800 micrograms/kg/day DOCA, and infused with 4, 25, 100 micrograms/kg/day angiotensin II (A II) or 0.9% saline. The three A II groups showed significant percentage changes in their saline intake above pre-A II levels; the saline control group showed no change in saline intake from pre-A II level. These results are interpreted to demonstrate the production of salt appetite in rats by peripheral administration of physiological doses of angiotensin II.