This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Dopamine all of the following is true Except? 
Select and explain. 
A. Causes increase in GI Isehemia, B. Positive ionotropic, C. Improves renal perfusion, D. Causes Vasoconstriction
A: Causes increase in GI Isehemia
Answer: A: Causes increase in GI Isehemia 
Explanation: Ans. is 'a' i.e., Causes increase in GI Ischemia o Dopamine acts on dopamine (Di & D2) and adrenergic (a1 + a2 + [31) receptors, with no action on p, receptors. o At lowest effective dose it stimulates D1 receptors in renal & mesentric blood vessels --> improves renal and mesentric perfusion. o At moderately high doses it acts as 13, agonist --> positive ionotropic. o At high doses it activates a-adrenoreceptors --> vasoconstriction.