This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Adrenergic System, Subject name: Pharmacology
Dopamine is preferred in treatment of shock because of: 
Select and explain. 
A. Renal vasodilatory effect, B. Increased cardiac output, C. Peripheral vasoconstriction, D. Prolonged action
A: Renal vasodilatory effect
Answer: A: Renal vasodilatory effect 
Explanation: Ans. (A) Renal vasodilatory effect(Ref: Katzung 11/e p137)Dopamine acts on D1 , b1 and a1 receptors. Stimulation of D1 receptors cause renal vasodilation, which is useful clinically to improve renal perfusion in shock with oligouria.