Dopamine in dose concentration at <2mcg/kg/min acts predominantly on?

Ans. B. D-1At low doses (<=2mg/kg/minute)stimulates dopaminergic receptors on renal blood vessels leading to vasodilation. DA infusion at this rate may increase renal blood flow and promote diuresis.At intermediate infusion rates (2-5mg/kg/min), (used in CHF, cardiogenic shock)Stimulates b1 receptors on heart increasing cardiac contractility. Also stimulates D1 receptorsAt higher infusion rates (5-15mg/kg/min), (used for shock with oliguria)Acts on a1, leading to vasoconstriction and rise in BP. Also stimulates D1 & b1 receptors