Production of the beta-amyloid precursor protein (beta APP) by bovine adrenal chromaffin cells was investigated by polymerase chain reaction (PCR) and by immunoblot. Chromaffin cells were found to synthesize forms of beta APP similar to those found in the rat PC12 pheochromocytoma cell line and to secrete these constitutively into their culture medium. Release of beta APP could be enhanced by stimulation with phorbol ester but not by cholinergic stimulation of secretion. The fact that normal chromaffin cells produce beta APP suggests that beta APP has some (as yet undermined) function in the adrenal medulla in vivo.