What is the direct effect of vasopressin on cerebral vasculature?

What is the direct effect of vasopressin on cerebral vasculature?

• A. Cerebral vasoconstriction
• B. Cerebral vasodilation
• C. No effect
• D. Increase in cerebral venous pressure

Answer: (A)

Vasopressin directly constricts vascular smooth muscle by activating V1 receptors, which raises intracellular calcium and causes contraction. In cerebral vessels, this direct receptor-mediated contraction leads to cerebral vasoconstriction, increasing vascular tone and resistance. While brain autoregulation can help maintain blood flow within certain MAP ranges, the immediate vascular response to vasopressin in the cerebrum is constriction, not dilation or no effect. An increase in cerebral venous pressure is not a direct result of the cerebral arterial smooth muscle contraction produced by vasopressin.

Vasopressin directly constricts vascular smooth muscle by activating V1 receptors, which raises intracellular calcium and causes contraction. In cerebral vessels, this direct receptor-mediated contraction leads to cerebral vasoconstriction, increasing vascular tone and resistance. While brain autoregulation can help maintain blood flow within certain MAP ranges, the immediate vascular response to vasopressin in the cerebrum is constriction, not dilation or no effect. An increase in cerebral venous pressure is not a direct result of the cerebral arterial smooth muscle contraction produced by vasopressin.