Effect of selective denervation of the rat pancreas on pancreatic endocrine function

The purpose of this study was to investigate the influence of selective denervation of the rat pancreas on hormone secretion and on peripheral insulin sensitivity. Thirteen rats, 7 denervated and 6 sham operated, received an intravenous glucose challenge for 30 min. The basal plasma levels of insulin, glucagon and glucose did not differ between the two groups. An augmented insulin response to glucose was detected in the denervated group, whereas the glucagon response was unaffected. Glucose tolerance was marginally improved. Twenty-four rats, 12 denervated and 12 sham operated, received a constant infusion of glucose, insulin, epinephrine and propranolol in order to inhibit the endogenous insulin release and thus evaluate insulin sensitivity. No significant change in insulin sensitivity could be detected during our experimental conditions. We conclude that selective denervation brings about an increased insulin response to glucose, probably by interrupting a catecholaminergic negative tone on the beta-cell. The sympathectomized animals did not disclose any apparent changes in peripheral insulin sensitivity.