Dobutamine primarily activates which receptor?

Dobutamine primarily activates which receptor?

• A. Beta-1 adrenergic receptor
• B. Alpha-1 adrenergic receptor
• C. Beta-2 adrenergic receptor
• D. Dopamine receptor D1

Answer: (A)

Dobutamine primarily activates beta-1 adrenergic receptors. When beta-1 receptors on cardiac myocytes are stimulated, cAMP rises, increasing calcium availability inside the cells. This boosts the heart's contractility (positive inotropy) and, to a lesser extent, heart rate, leading to a higher cardiac output. Its beta-2 activity can cause mild vasodilation, which lowers afterload, and it has minimal alpha-1 activity, so it doesn’t cause significant vasoconstriction. This combination makes dobutamine ideal for improving cardiac output in heart failure or cardiogenic shock by mainly acting on the heart rather than causing vasoconstriction.

Dobutamine primarily activates beta-1 adrenergic receptors. When beta-1 receptors on cardiac myocytes are stimulated, cAMP rises, increasing calcium availability inside the cells. This boosts the heart's contractility (positive inotropy) and, to a lesser extent, heart rate, leading to a higher cardiac output. Its beta-2 activity can cause mild vasodilation, which lowers afterload, and it has minimal alpha-1 activity, so it doesn’t cause significant vasoconstriction. This combination makes dobutamine ideal for improving cardiac output in heart failure or cardiogenic shock by mainly acting on the heart rather than causing vasoconstriction.