Endocrine response to intragastric and intravenous glucose challenge in the denervated dog pancreas

The functional connection between the gut and the islet cells comprises nerves and gastrointestinal hormones. In this study, we quantified the incretin effect and the glucose tolerance (KG value) before and after denervation of the pancreas in dogs in order to find out whether the incretin effect is mediated by nerves. The participation of nerves was estimated by comparing metabolic tests before and after total extrinsic pancreatic denervation in 10 dogs. Fifty-nine percent of the insulin response after intragastric glucose was calculated preoperatively to be the result of incretin factors, a value similar to the 62% found in the postoperative series (with denervated pancreas). The response of GIP to intragastric glucose was not significantly different between pre- and postoperative tests. The KG values pre- and postoperative were in the same range. From our data, we conclude that extrinsic nerves of the pancreas do not seem to play an important role in mediating glucose homeostasis in dogs.