A Rat Pancreas-Small Gut Preparation for the Study of Intestinal Factor(s) and Insulin Release

Abstract

A technic for in situ perfusion of rat pancreas alone or with a small intestine preparation, which is suitable for studying insulin and/or glucagon secretion and the role intestinal factor(s) has upon it, is described. Krebs- Ringer bicarbonate buffer, containing 4.0 per cent bovine albumin and 80 mg. per 100 ml. glucose with pH adjusted to 7.4, was used as perfusate. When the pancreas was perfused with a nonrecirculated buffer there was no significant change in the levels of glucose or insulin in the perfusate, while with recirculated buffer, there was a decrease in both measurements. When additional glucose was added to the perfusate, there was an increase of insulin levels, more marked in the pancreas perfusion with recirculated buffer (possibly pancreatic glucagon plus glucose effect) than in nonrecirculated ones (glucose effect). In pancreas-intestine perfusion with recirculated buffer, there was a decrease of the levels of insulin and glucose, and when additional glucose was added to the perfusate, there was an increase of the levels of insulin and glucose (possibly pancreatic glucagon and glucose effect). When glucose was passed through the intestine, there was a marked increase of the levels of insulin which was significantly higher than the previous group studied, probably due to the effects of glucose, pancreatic glucagon and intestinal factors. It may be possible by the results obtained to separate the effects of the three factors on the release of insulin: glucose, glucagon and intestinal factor(s).