Endogenous catecho l amines--Dopami ne Dopamine receptors D1-5 D1:couples to Gs and adenylyl cyclase.In vascular beds especial ly renal,mesenteric and coronary beds.Lead to vasodi lation. D2:couples to Gi to inhibit adenylyl cyclase.Presynaptic distribution. Stimulation of D2 receptors suppress norepinephrine release contribute to the vasodi lation effects.Endogenous catecholamines--Dopamine Dopamine receptors D1-5 D1: couples to Gs and adenylyl cyclase. In vascular beds especially renal, mesenteric and coronary beds. Lead to vasodilation. D2: couples to Gi to inhibit adenylyl cyclase. Presynaptic distribution. Stimulation of D2 receptors suppress norepinephrine release contribute to the vasodilation effects