Hepatic glucose signals vagally modulate the cyclicity of gastric motility in rats.

The cyclicity and intensity of gastric motility were examined following glucose injection into the portal vein with an intragastric balloon in anesthetized rats. Enhanced gastric motility caused by insulin administration was influenced by 4 mM glucose (25 microliters) injected into the portal vein; glucose provoked a shift in the cyclicity power spectrum without any change in intensity. The peak power spectrum shifted from 4.0-5.0 cpm to 2.0-3.0 cpm. Hepatic branch vagotomy abolished the response. The results suggest that glucose signals in the hepatic vagal branch modulate the cyclicity of gastric motility.