Effect of cadmium and bombesin on exocrine pancreatic secretions and plasma levels of gastrin and cholecystokinin (CCK) in rats.

The effects of cadmium and bombesin on exocrine pancreatic secretions and plasma levels of gastrin and cholecystokinin (CCK) were studied in anesthetized rats with pancreatic and gastric fistulas. Rats treated only with saline were used as controls. Both control and cadmium (0.1 mg per kg) treated rats were infused with saline, secretin, and bombesin (BBS). Blood and pancreatic juice samples were collected at regular time intervals. Plasma levels of gastrin and CCK were measured in blood samples by specific radioimmunoassay. Pancreatic juice samples were measured for volume, protein, and trypsin outputs. Compared to saline treated rats, outputs of volume, protein, and trypsin were significantly greater in cadmium treated rats. Plasma levels of gastrin were suppressed with secretin but significantly elevated with BBS. Plasma CCK levels were not different from basal after secretin or BBS in rats treated with either cadmium or saline. The results suggest that the administration of cadmium stimulated exocrine pancreatic secretion by a mechanism that does not involve gastrin or CCK. Bombesin may have a direct influence on the stimulation of exocrine pancreatic secretion in rats.