EXPRESSION OF RECEPTORS FOR GUT PEPTIDES IN PANCREASES OF BOP-TREATEDAND CONTROL HAMSTERS

The growth of pancreatic cancers may be influenced by certain gut pept ides, However, the alteration of gut peptide receptors in the progress of pancreatic carcinogenesis is largely unknown, With storage phospho r autoradiography, this study visualized and characterized receptors f or cholecystokinin (CCK), somatostatin (SST), bombesin (BBS), secretin and vasoactive intestinal peptide (VIP) in pancreata of control hamst ers (n = 7) and pancreatic preneoplastic lesions (n = 10) or adenocarc inomas (n = 10) of N-nitrosobis(2-oxopropyl)amine (BOP)-treated hamste rs. The specific CCK-A and secretin receptors expressed in normal panc reata were markedly reduced in pancreatic preneoplastic lesions and ab sent in adenocarcinomas. In the development of pancreatic tumours, the subgroup of SST receptors did not change, but both the affinity and b inding capacity declined, In comparison with the binding of VIP to nor mal pancreata, specific VIP binding was significantly lower in preneop lastic lesions and almost absent in pancreatic adenocarcinomas, No spe cific binding for BBS was detected in normal pancreas or (pre)neoplast ic lesions of hamster pancreas, The reduction or absence of receptors for CCK, secretin, SST and VIP in hamster pancreas with the progress o f carcinogenesis suggests that in POP-treated hamsters, pancreatic ade nocarcinomas have, to a large extent, lost the hormone-dependent chara cteristics of the original tissue.