Dopaminergic receptors are primarily associated with which effect?

• A. Renal and mesenteric vasodilation
• B. Beta 1 receptors
• C. V2 receptors
• D. V1 receptors

Answer: (A)

Dopaminergic (D1-like) receptors mainly cause dilation of renal and mesenteric blood vessels. When these receptors are activated in the renal vasculature, smooth muscle relaxes via a Gs-coupled mechanism that increases cAMP, leading to vasodilation, increased renal blood flow, and often enhanced diuresis. This is the characteristic effect that sets dopaminergic action apart from other receptor systems. In contrast, beta-1 receptors primarily drive changes in the heart (increased rate and contractility), V1 receptors cause vasoconstriction in vascular smooth muscle, and V2 receptors promote water reabsorption in the kidney. So the key dopaminergic effect you’re testing is renal and mesenteric vasodilation.