Inhibition of gastric motility induced by hepatic portal injections of D-glucose and its anomers

Intragastric pressures were recorded in bilaterally adrenalectomized male rats with insulin hypoglycaemia. A significant depression in intragastric pressure was noted following the administration of D-glucose injected into the hepatic portal vein but not after the administration of L-glucose, D-mannose, D-fructose, D-galactose, D-xylose or D-arabinose. The reduction in intragastric pressure induced by the portal administration of D-glucose was not reproduced following selective division of the hepatic branch of the vagus nerve. Of the three anomeric forms of D-glucose used (alpha-D-glucose, equilibrated D-glucose and beta-D-glucose), beta-D-glucose was most potent in reducing the intragastric pressure. These results suggest that the vagal afferents may convey information concerning glucose concentration in the portal vein to the central nervous system, and that the activation of such afferents may modulate gastric motility which is dependent on the anomeric stereospecificity of D-glucose.