ATP STIMULATED CATECHOLAMINE SECRETION - RESPONSE IN PERFUSED ADRENAL-GLANDS AND A SUBPOPULATION OF CULTURED CHROMAFFIN CELLS

Extracellular ATP is shown to induce catecholamine secretion in bovine chromaffin cells. Our data indicate that cells in culture gradually i ncrease their response to ATP, and we have separated freshly isolated cells on a density gradient and found that the lighter cells develop a much stronger response to ATP than do the heavier cells. To see if th e ATP sensitivity is physiological, we have perfused intact adrenal gl ands. ATP induces a greater secretory response from glands than does a cetylcholine without causing preferential secretion of norepinephrine or epinephrine. These data show that the response to ATP found in cult ured cells is not an artifact of cell culture, and that ATP co-release d with catecholamines from the storage vesicles may have a significant physiological role.