Effect of serum on adrenal PNMT activity.

Humoral mechanism should be responsible for activation of PNMT (phenylethanolamine N-methyltransferase) by CRF (corticotropin-releasing factor) in vivo (Lima and Sourkes, 1987). Small amounts of serum (10 microliters) caused a sig. dose dependent activation of bovine PNMT activity (19.