Salt preference elicited by chronic intracerebroventricular angiotensin II

1. Much more water was consumed than either 0.9% or 2.7% saline in response to various dipsogenic stimuli in untreated normal replete rats when they had free access to water, 0.9% and 2.7% saline. On the other hand, the rats drank more 0.9% saline than water and 2.7% saline when each solution is the sole drinking fluid offered. 2. A marked increase in preference for 0.9% saline was observed during the chronic i.c.v. injection of angiotensin II at a dose of 25 ng/hr for 7 consecutive days in the three bottle choice test. After the cessation of angiotensin II infusion, most rats (45 out of 50 rats) returned to drink much more water than 0.9% and 2.7% saline, similar to the drinking pattern of the 0.9% saline-treated control rats. However, some rats (5 out of 50 rats) still preferred 0.9% saline and this persisted for up to 3 months although these rats did not show a hypertensive state and an increase of plasma renin activity.