Multiple populations of neuropeptide-containing cells in cultures of the bovine adrenal medulla.

Cell populations containing vasoactive intestinal polypeptide (VIP), enkephalins, and catecholamines were identified in bovine adrenal medullary cultures by immunofluorescence and radioimmunoassay. Addition of forskolin to the culture medium increased the cellular levels of both VIP and the enkephalins. These changes resulted from an increase in the number of VIP-positive cells and an increase in cellular enkephalin content.