国 Catecho l amines Natural ·Norep i nephr ine:,B1 ·Epinephr ine:,B ·Dopamine:D,1,β1(also some NE release) Synthetic ·Isoproterenol:B ·Dobutamine:β1(and mix of B2 stimulation and a inhibition and stimulation)Natural • Norepinephrine:  , 1 • Epinephrine: ,  • Dopamine: D, 1 , 1 (also some NE release) Synthetic • Isoproterenol:  • Dobutamine: 1 (and mix of 2 stimulation and 1 inhibition and stimulation) Catecholamines