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
[{'content': 'Which is True about dobutamine ? \nSelect and explain. \nA. Dobutamine decreases peripheral resistance, B. Acts on D1 and D2 receptors, C. Decrease kidney circulation, D. Has no effect on coronary circulation', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Dobutamine acts by activating β1\xa0 receptors and may\xa0decrease the peripheral resistance by its minor effect\xa0on β2 receptors. It has no effect on dopamine D1 or D2\xa0receptors.\n\nDobutamine is a direct-acting inotropic agent whose\xa0primary activity results from stimulation of the β receptors of the heart while producing comparatively\xa0mild chronotropic, hypertensive. Arrhvthmogenic,\xa0and vasodilative effects. It does not cause the release\xa0of endogenous norepinephrine, as does dopamine. In\xa0animal studies, dobutamine produces less increase in\xa0heart rate and less decrease in peripheral vascular resistance for a given inotropic effect than does isoproterenol.\xa0\nSystemic vascular resistance is usually decreased with\xa0administration of dobutamine. Occassionally minimum vasoconstriction has been observed. Similarly coronary blood flow may be increased with dobutamine.', 'role': 'assistant'}]