EVIDENCE FOR CHOLECYSTOKININ(A) RECEPTORS IN BOVINE ADRENAL CHROMAFFIN CELLS

WE have studied a possible role of cholecystokinin (CCK) in regulating adrenal medullary function. Caerulein (10(-10)-10(-7) M), a CCK recep tor agonist, increased formation of inositol phosphates in primary cul tured bovine adrenal medullary (BAM) chromaffin cells in a concentrati on-dependent manner. The effect of caerulein was antagonized by devaze pide, a selective CCKA-receptor antagonist, but not by L-365.260, a se lective CCKB-receptor antagonist. These results suggest that BAM cells possess functional CCK receptors of the CCKA-subtype. Stimulation of these receptors with caerulein activates a signal transduction pathway via phospholipase C. CCK may regulate catecholamine release in BAM ce lls.