Endogenous catecho l amines--Dopami ne 【pharmaco|ogical properties】 > Cardiovascular effects:dose-dependent effects > At low concentration (10u g/kg/min),dopamine stimulates D1 receptor in vascular beds and causes vasodilation.An increase in glomerular filtration rate,renal blood flow,and Na excrection. > At higher concentration (20u g/kg/min),it stimulates cardiac B1 receptors which leads to an increase in cardiac contractility and cardiac output. > At high concentration,dopamine may activate vascular a adrenergic receptor which causes vasoconstriction,elevates blood pressure.Endogenous catecholamines--Dopamine 【pharmacological properties】  Cardiovascular effects: dose-dependent effects  At low concentration (10μg/kg/min), dopamine stimulates D1 receptor in vascular beds and causes vasodilation. An increase in glomerular filtration rate, renal blood flow, and Na excrection.  At higher concentration (20μg/kg/min), it stimulates cardiac β1 receptors which leads to an increase in cardiac contractility and cardiac output.  At high concentration, dopamine may activate vascular α adrenergic receptor which causes vasoconstriction, elevates blo od pressure