Examination was made of the direct vascular effects of the hypertension-inducing pressor hormone angiotensin II on expression and activity of the voltage-gated calcium channel CaV1.2. Freshly dissected rat superior mesenteric artery beds were maintained in organ culture unpressurized for 24 h in the presence or absence of angiotensin II. Relative to controls, angiotensin II increased CaV1.2 protein expression and tension-inducing activity but not CaV1.2 message. The increase in CaV1.2 protein expression by angiotensin II was abrogated by damaging the endothelium. Thus, the endothelium is involved in regulating CaV1.2 expression in the vascular wall.