Low-dose dopamine (1-5 mcg/kg/min) primarily stimulates which receptors?

• A. Dopaminergic receptors
• B. B1-adrenergic receptors
• C. Alpha-adrenergic receptors
• D. Muscarinic receptors

Answer: (A)

Low-dose dopamine primarily activates dopaminergic receptors (D1) in renal and mesenteric vascular beds, causing vasodilation and increased renal blood flow with enhanced diuresis. This dose-dependent effect means that at low doses the renal-directed dopamine receptor stimulation dominates, while higher doses recruit beta-adrenergic (B1) or alpha-adrenergic receptors and do not primarily involve dopaminergic pathways. Muscarinic receptors are not influenced by dopamine. Therefore, the best answer is dopaminergic receptors.