Primary cultures of bovine chromaffin cells synthesize and secrete vasoactive intestinal polypeptide (VIP)

Dispersed cells of the bovine adrenal medulla express immunoreactive vasoactive intestinal polypeptide (VIP) after 24 hours in culture, although VIP could not be detected in extracts of bovine adrenal medulla or cortex. Immunoreactive VIP eluted from a reversed-phrase chromatography column with the same retention time as authentic porcine VIP1-28. VIP in chromaffin cells in culture appears to be contained in a secretory granule pool, since it, like methionine-enkephalin (met-enk) was released into the medium after exposure of cells to nicotine, carbachol, veratridine and elevated potassium in a dose-dependent manner. Dose-response curves for VIP and enkephalin release by the above secretagogues were similar but not identical. Enkephalins and VIP may either be contained in separate subpopulations of chromaffin cells or co-stored in the same cells.