drug concentrations for 50 % maximum response for the effect of a series of adrenergic agonists on scc were ( in m ) isoproterenol 1.2 +/- 0.05 x 10 ( -8 ) , norepinephrine 6.1 +/- 0.3 x 10 ( -8 ) , epinephrine 2.4 +/- 0.1 x 10 ( -7 ) , and phenylephrine 4.7 +/- 0.2 x 10 ( -5 ) , suggesting the involvement of fetally oriented beta-adrenergic receptors .
C0028351
norepinephrine
C0014563
epinephrine