TEMPORAL EXPRESSION OF THE GASTRIN (CCK-B) RECEPTOR DURING AZASERINE-INDUCED PANCREATIC CARCINOGENESIS

Cholecystokinin (CCK-A) and gastrin (CCK-B) receptors have been demons trated in the azaserine-induced rat pancreatic carcinoma DSL-6. In ord er to determine at what stage in azaserine-induced pancreatic carcinog enesis gastrin (CCK-B) receptors are first expressed, we examined the binding of [I-125]gastrin-I to normal rat pancreas, azaserine-induced premalignant pancreatic nodules, grossly normal internodular pancreas, and DSL-6 carcinoma. We observed that specific gastrin binding was ab sent in normal pancreas, premalignant nodules, and internodular pancre as, and also reconfirmed our previous report of marked overexpression of gastrin (CCK-B) receptors in the DSL-6 carcinoma. Specific cholecys tokinin (CCK) binding was present in all pancreatic tissue types teste d. Therefore, we conclude that the presence of gastrin (CCK-B) recepto rs in the azaserine-induced pancreatic carcinoma DSL-6, in contrast to their absence in premalignant nodules, suggests that the expression o f the gastrin (CCK-B) receptor may be important in the transformation from premalignant nodules to pancreatic cancer.