however a potency difference of 100-fold for isoproterenol ( ic50 = 4.80 x 10 ( -8 ) m for efs and 3.70 x 10 ( -6 ) m for ach ) and 10-fold for both epinephrine and norepinephrine was observed for inhibition of responses to efs compared with responses to ach .
C0014563
epinephrine
C0028351
norepinephrine