Pituitary tumors containing cholecystokinin.

We found small amounts of cholecystokinin in the normal human adenohypophysis and therefore examined pituitary tumors from 87 patients with acromegaly, Cushing's disease, Nelson's syndrome, prolactinoma, or inactive pituitary adenomas. Five adenomas associated with Nelson's syndrome contained increased amounts of cholecystokinin, the concentrations being extremely high in two: 8281 and 13,453 pmol per gram as compared with less than 30 pmol per gram in normal pituitary glands. The cholecystokinin concentrations were moderately increased in adenomas from another 12 patients, of whom 5 had Cushing's disease and 7 acromegaly with adenomas containing ACTH. The cholecystokinin peptides from the tumors were smaller and less sulfated than cholecystokinin from normal pituitary glands. We conclude that ACTH-producing pituitary cells may also produce an altered form of cholecystokinin.