Metabolic and Neuroendocrine Consequences of a Duodenal-Jejunal Bypass in Rats on a Choice Diet

Objective: We sought to examine insulin-sensitive food intake behavior and neuroendocrine and metabolic variables of rats that had undergone a duedenal-jejunal bypass (DJB). Summary of Background Data: A DJB that circumvents the duodenum and proximal jejunum while leaving the stomach unperturbed rapidly improves insulin sensitivity in type 2 diabetic rats. This segment of proximal small intestine is innervated by the gastroduodenal branch Of the vagus nerve, the transection of which influences food intake choices in streptozotocin-diabetic rats. Methods: Rats were first placed on a choice of chow and lard for 7 days and additionally provided with an enriched liquid diet for another 7 days before Surgery and were allowed only the liquid diet for 7 days after either a sham or DJB operation. Results: After surgery, DJB-operated rats initially consumed less than the sham-operated counterparts. When the rats were subsequently provided with the choice of chow and lard for 7 days there were no differences in intake between the DJB and sham-operated groups. Similarly, the majority of metabolic and neuroendocrine variables measured were unchanged. However, DJB-operated rats exhibited greater mesenteric white adipose tissue weight, fecal output, arcuate nucleus neuropeptide Y mRNA expression, plasma corticosterone, and glucagon levels together with reduced plasma leptin concentrations. Conclusions: DJB surgery does not produce significant differences in food intake choices after a period of recovery; however, there are enduring metabolic and neuroendocrine changes, which are collectively important to understanding the beneficial outcomes of the operation.