Abstract
We investigated whether chronic subcutaneous infusion of neurotensin during 14 days would affect pancreatic and gastric growth of rats. In another experiment, neurotensin (836 pmol/kg) was injected intraperitoneally three times a day for three days in 12 rats. Thereafter, pancreatic DNA and in vitro incorporation of 3H-thymidine into pancreatic DNA was determined. Long term infusion of 282 pmol/kg neurotensin induced an increase of pancreatic weight, DNA, and pancreatic polypeptide, whereas pancreatic protein, RNA, amylase and lipase contents were not increased. In relation to DNA, even these parameters were significantly depressed. Insulin remained unchanged. Neurotensin, therefore, caused hyperplasia of the pancreas. Intraperitoneal injection of neurotensin induced an increase of pancreatic DNA content and stimulated 3H-thymidine incorporation into DNA, whereas caerulein only augmented 3H-thymidine incorporation. Moreover, long term neurotensin infusion led to a rise in protein concentration and an increase in the thickness of the gastric antrum; antral DNA concentration was insignificantly stimulated. Neurotensin, therefore, can act as a trophic factor on pancreas and gastric antrum of the rat.