Beta-2 receptor activation leads to which combination of effects?

Beta-2 receptor activation leads to which combination of effects?

• A. Vasodilatory only
• B. Vasodilation and bronchodilation
• C. Bronchodilation only
• D. No effect

Answer: (B)

Beta-2 receptor activation triggers a Gs-coupled response that raises cyclic AMP in smooth muscle, causing relaxation. In the airways, this relaxes bronchial smooth muscle, leading to bronchodilation. In certain vascular beds, especially in skeletal muscle, the same signal relaxes vascular smooth muscle, producing vasodilation. So the net effects are both bronchodilation and vasodilation. This is why beta-2 agonists relieve airway constriction and can cause peripheral vasodilation.

Beta-2 receptor activation triggers a Gs-coupled response that raises cyclic AMP in smooth muscle, causing relaxation. In the airways, this relaxes bronchial smooth muscle, leading to bronchodilation. In certain vascular beds, especially in skeletal muscle, the same signal relaxes vascular smooth muscle, producing vasodilation. So the net effects are both bronchodilation and vasodilation. This is why beta-2 agonists relieve airway constriction and can cause peripheral vasodilation.