Effects of ethanol on plasma catecholamines and norepinephrine clearance

Plasma catecholamines were measured in nine men after they had drunk either 0.5 or 1 ml/kg ethanol. Ethanol was found to induce a dose-dependent rise in plasma norepinephrine concentrations. Epinephrine concentrations were also raised in the initial intoxication phase. To determine whether ethanol raises plasma norepinephrine through increased release or decreased clearance (Cl), we infused norepinephrine into eight male subjects with and without prior ethanol, each subject acting as his own control. During infusions after ethanol, norepinephrine concentrations rose higher, and the mean circulatory Cl of norepinephrine was reduced from 76 to 47 ml/kg/min. This was associated with a prolongation of norepinephrine t 1/2 from 1.7 to 2.05 min. No significant difference in circulatory input of norepinephrine was found between infusions with and without ethanol. These results indicate that ethanol consumption increases plasma norepinephrine by reducing its circulatory Cl.