Strong alpha effects produce what clinical consequence?

Strong alpha effects produce what clinical consequence?

• A. Decreased BP
• B. Strong vasoconstriction
• C. Bronchodilation
• D. Decreased HR

Answer: (B)

Alpha-adrenergic stimulation on vascular smooth muscle drives vasoconstriction. Activation of alpha-1 receptors triggers a Gq signaling cascade that raises intracellular calcium, causing contraction of arterioles (and venules). This narrows the vessels, increases systemic vascular resistance, and raises blood pressure. Bronchodilation comes from beta-2 receptors, not alpha, so strong alpha effects don’t produce bronchodilation. A rise in blood pressure from vasoconstriction can provoke a reflex change in heart rate, but the direct and primary clinical consequence of strong alpha activity is vasoconstriction with increased BP.

Alpha-adrenergic stimulation on vascular smooth muscle drives vasoconstriction. Activation of alpha-1 receptors triggers a Gq signaling cascade that raises intracellular calcium, causing contraction of arterioles (and venules). This narrows the vessels, increases systemic vascular resistance, and raises blood pressure. Bronchodilation comes from beta-2 receptors, not alpha, so strong alpha effects don’t produce bronchodilation. A rise in blood pressure from vasoconstriction can provoke a reflex change in heart rate, but the direct and primary clinical consequence of strong alpha activity is vasoconstriction with increased BP.