Effects of propranolol on induced water intake and on the subfornical organ surface.

The chronic effect of propranolol on induced water intake and on the subfornical organ was studied. Propranolol reduced water intake postdehydration. It did not inhibit the increase in plasma renin activity due to dehydration or the dipsogenic response to angiotensin II. Propranolol decreased the subfornical organ large protrusion cells. This result suggests that propranolol impairs the thirst not related to angiotensin II. The subfornical organ changes may indicate that propranolol blocks a beta-adrenergic system originating in ependymal cells.