The molecular nature of cholecystokinin in the feline pancreas and related nervous structures.

Nerve terminals in pancreatic islets and ganglia containing cholecystokinin (CCK)/gastrin-like peptides are particularly abundant in the cat. In order to elucidate the possible origin and molecular nature of the peptides in these nerves, extracts of the feline pancreas, vagus, sympathetic trunk, and celiac-superior mesenteric ganglion were examined by gel chromatography monitored by sequence-specific radioimmunoassays. Small amounts of CCK-33 and CCK-8 were present in the pancreatic terminals. In the vagus and the sympathetic trunk, CCK, mainly as CCK-8, occurred in concentrations of 3.5 and 3.7 pmol/g. The celiac-superior mesenteric ganglion contained 40 pmol CCK/g distributed in five forms, including a predominant CCK-8-like component and a component eluting like CCK-4. Gastrins were not detected in the nervous structures. The results suggest that the celiac-superior mesenteric ganglia, the vagal nerves and the sympathetic trunks all may contribute to the CCK nerve terminals in the feline pancreas.