the plasma catecholamine concentrations reflected the different sites of action of the drugs in the sympathoadrenal system , i.e . guanethidine mainly reduced circulating norepinephrine and dopamine-beta-hydroxylase by more than 50 % , whereas emd 21192 decreased considerably by the total catecholamines ( mainly epinephrine ) without altering significantly in the plasma norepinephrine .
C0007412
total catecholamines
C0028351
norepinephrine