Which receptor mediates vasoconstriction?

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Multiple Choice

Which receptor mediates vasoconstriction?

Vasoconstriction in the peripheral vessels is mediated by alpha-1 adrenergic receptors on vascular smooth muscle. When activated by norepinephrine, these receptors couple to a Gq protein, which triggers phospholipase C, generating IP3 and DAG and raising intracellular calcium. The calcium rise causes smooth muscle contraction, narrowing arterioles and venules and increasing vascular resistance. Beta-1 receptors are mainly in the heart, increasing heart rate and contractility rather than directly constricting vessels. Beta-2 receptors promote vasodilation in skeletal muscle via a cAMP-mediated relaxation. There isn’t a gamma receptor involved in this vasoconstriction pathway.

Vasoconstriction in the peripheral vessels is mediated by alpha-1 adrenergic receptors on vascular smooth muscle. When activated by norepinephrine, these receptors couple to a Gq protein, which triggers phospholipase C, generating IP3 and DAG and raising intracellular calcium. The calcium rise causes smooth muscle contraction, narrowing arterioles and venules and increasing vascular resistance. Beta-1 receptors are mainly in the heart, increasing heart rate and contractility rather than directly constricting vessels. Beta-2 receptors promote vasodilation in skeletal muscle via a cAMP-mediated relaxation. There isn’t a gamma receptor involved in this vasoconstriction pathway.

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