The effect of jejunoileal bypass (JIB) in the obese Zucker rat on a sub-group of enteroendocrine cells

The effect of jejunoileal bypass in lean and obese Zucker rats on a number of enteroendocrine cell types was investigated 5 weeks following surgery to remove 80 percent of the small bowel from continuity. The endocrine cells containing somatostatin, cholecystokinin, gastric inhibitory polypeptide, enteroglucagon and neurotensin were investigated. In control rats enteroglucagon cell number was decreased in obese compared to lean animals (5 +/- 1 vs 11 +/- 1 cells/mm). Following jejunoileal bypass the enteroglucagon cell population increased two-fold in both the functional and bypassed bowel in obese rats but was not elevated in lean animals. A significant increase in the number of cholecystokinin cells in the bypassed loop of the jejunum in both lean and obese bypassed rats was observed. The cholecystokinin cell population was also markedly elevated in the functional jejunum of obese but not lean bypassed rats. Only small changes were noted in cell numbers of gastric inhibitory polypeptide, somatostatin and neurotensin containing cells, suggesting that individual cell types have specific stimuli for proliferation. Epithelial height, a measure of intestinal adaptation, was similar in lean and obese rats in both the control and bypassed states, but weight loss in obese bypassed animals was significantly greater than that of lean bypassed rats. The hyperinsulinemia of obese rats was only partially normalized by jejunoileal bypass. These data indicate that jejunoileal bypass has effects on specific enteroendocrine cells which differ between lean and obese Zucker rats, and between individual cell types.(ABSTRACT TRUNCATED AT 250 WORDS)