Renal dose of dopamine is-
**Core Concept**
Dopamine is a catecholamine with varying effects on the body depending on the dose. At low doses, it has vasodilatory effects on renal and mesenteric arteries, potentially increasing renal blood flow and glomerular filtration rate. This property is exploited in the treatment of acute kidney injury or oliguria.
**Why the Correct Answer is Right**
The renal dose of dopamine, typically in the range of 1-3 μg/kg/min, acts primarily on D1 receptors in the renal vasculature. Activation of these receptors leads to vasodilation of the afferent arterioles, increasing renal blood flow and potentially improving glomerular filtration rate. This mechanism is thought to be beneficial in patients with acute kidney injury or those at risk of renal hypoperfusion.
**Why Each Wrong Option is Incorrect**
**Option A:** This dose range is generally too low to produce significant renal vasodilation and is more commonly associated with effects on the heart and peripheral vasculature.
**Option B:** This dose range is typically associated with more pronounced effects on the cardiovascular system, including increased heart rate and contractility, rather than renal vasodilation.
**Option C:** This dose range is often associated with more pronounced effects on the sympathetic nervous system, including increased blood pressure and peripheral vasoconstriction, rather than renal vasodilation.
**Clinical Pearl / High-Yield Fact**
When using dopamine for renal dose effects, it is essential to monitor blood pressure and cardiac output closely, as higher doses can have deleterious effects on the cardiovascular system.
**Correct Answer:** C. 2-5 μg/kg/min