Among the following propeies of dopamine, which of them is not helpful in acute shock?
(A) Alpha-1 agonist action leading to peripheral vasoconstriction (B) Increase in renal perfusion due to agonist action on DI receptors (C) Releases noradrenaline and causes positive inotropic effect (D) Direct action on hea beta-1 receptors
(B) Ans: B. Increase in renal perfusion due to agonist action on DI receptors(Ref: Goodman Gilman 13Ie p1062, 12/e p355; KDT 71e p134, 6Ie p507)Dopamine at low concentrations (2 to 5 mug/kg per minute) primarily acts on vascular D, receptors, especially in the renal, mesenteric, and coronary beds.Increased renal perfusion caused by dopamine due to DI agonism (at low doses) doesn't improves survival in acute shock.