Proximal gastric vagotomy: effects of two surgical modifications on oral and intravenous glucose tolerance in the conscious rat.

Vago-vagal nervous links between different splanchnic organs, the stomach included, may modulate glucose metabolism. Therefore, the effect of highly selective (HSV, cutting nerve fibers and vessels) and superselective vagotomy (SSV, cutting nerve fibers only) on oral and intravenous (IV) glucose tolerance was studied in the rat. Gastric emptying was normal in HSV and SSV. After oral glucose, cumulative blood glucose and insulin were significantly lower in SSV than in controls, whereas in HSV, both parameters tended towards lower values. After IV glucose, cumulative blood glucose was significantly lower than in controls following both vagotomies, whereas cumulative insulin was lower in HSV and significantly higher in SSV. The former effect may be insulin-independent. The latter reflects enhanced insulin sensitivity in HSV and increased glucose-stimulated insulin release in SSV. The improvement of oral and IV glucose tolerance by both procedures may reflect the abolition of physiological vagal (SSV) or partial abolition of sympathetic (HSV) nervous links between the stomach and the pancreas, which modulate insulin secretion or organ sensitivity to insulin.