The alpha 1D-adrenergic receptor modulates cardiovascular and drinking responses to central salt loading in mice

To characterize the involvement of specific alpha(1)-adrenergic receptor (alpha(1)-AR) subtypes in hypertension, parameters related to central salt- or angiotensin II (ANG II)-induced hypertension were investigated in alpha(1D)-AR-deficient mice (knockout). Baseline daily water intake and food intake were larger in alpha(1D)(-/-) mice than in alpha(1D)(+/+) mice. Intracerebroventricular (i.c.v.) administration of NaCl (0.67 M NaCl, 1 microl) elicited smaller increases in mean arterial blood pressure (MABP), heart rate, and water intake in alpha(1D)(-/-) mice than it did in alpha(1D)(+/+) mice. I.c.v. administration of ANG II (10 pmol) resulted in increases in MABP and water intake that were similar in alpha(1D)(-/-) mice and alpha(1D)(+/+) mice. These results suggest that alpha(1D)-AR is, at least in part, involved in central salt-induced but not ANG II-induced hypertension and water intake.