Experimental Studies on the Surgical Significance of the Trophic Action of Gastrointestinal Hormones on the Pancreas

The trophic actions of pentagastrin, pancreozymin and cholecystokinin on the pancreas of rats were investigated. The results obtained were as follows. 1) Chronic administration of these hormonal drugs increased the pancreatic weight, pancreatic DNA, RNA and protein contents as compared with the control saline-treated rats. As pentagastrin-treated group didn't produce any significant increase in DNA content in 100 mg of the pancreatic tissue and RNA : DNA ratio as compared with the control group, it was thought that the trophic action of pentagastrin may be rather due to the hyperplasia of the pancreatic cells than their hypertrophy. 2) ^<3>H-thymidine incorporations into pancreatic and duodenal DNA after a single injection of pentagastrin or cholecystokinin were increased as compared with the control saline-injected group. It was considered that gastrin and CCK-PZ stimulate the proliferation or regeneration of the pancreatic and duodenal cells. 3) A single injection of pentagastrin resulted in a marked increase in amylase output and the slight increases in pancreatic flow and bicarbonate output. It was recognized that pentagastrin stimulate the exocrine function of the pancreas of rats. 4) Hemigastrectomy including duodenal segment was performed to remove the gastrin cells. The pancreatic weight, pancreatic DNA, RNA and protein contents were reduced after surgery. Pentagastrin ameliorated such pancreatic atrophy to the similar degree to the control group. It was considered that endogenous gastrin is an important regulator of the pancreas and exogenous gastrin is able to protect against the pancreatic atrophy due to the lack of gastrin cells. According to these aspects, it is noteworthy that after the operative removal of these hormonal cells, their trophic actions may be disappeared. And it is suggested that these hormones may be applicable to the patients suffering from postoperative pancreatic insufficiency or atrophy and chronic pancreatitis.