The relationships between glucose absorption and insulin secretion and the migrating myoelectric complex in the pig

Abstract

SUMMARYNet glucose and free amino nitrogen absorption and insulin output in the pig hepatic portal vein were calculated from portal-arterial concentration differences and portal blood flow measured by thermodilution. Duodenal and jejunal motility were assessed by electromyography. In the fed pig, the migrating myoelectric complex (MMC) pattern of motility persisted; glucose and amino nitrogen absorption and insulin secretion all varied with the phase of the MMC, rising to maximum values 194+3-1 min before and falling to minimum values 167 + 44 min after phase III. The variations in glucose absorption with the MMC were caused primarily by changes in duodenal and jejunal motility rather than by changes in the rate of gastric emptying as glucose absorption and insulin secretion varied with the phase of the MMC during duodenal glucose infusions, with maximum values occurring 244 + 3-3 min before and minimum values 149 + 25 min after phase III activity. The mean glucose absorption time calculated by timing the appearance of glucose in the portal vein following an intraduodenal bolus injection was significantly longer when given in phase I showing that absorption was less rapid when the intestine was not contracting. A significant amount of glucose is metabolized by intestine, as during glucose infusion (500 mg min-1) the average portal glucose absorption (376 mg min-1) was less than the glucose infused.

Effect of the glucagon-like peptide-1 receptor agonist lixisenatide on postprandial hepatic glucose metabolism in the conscious dog

“…Additionally, the absorption of a meal is not a smooth process but instead occurs in a rhythmic pattern induced by the migrating myoelectric complex (9,45). This has been observed to entrain insulin secretion (45). Overall, our data from the lixisenatide group agree with those of Lorenz et al (27) obtained in the human in that postprandial insulin secretion appeared to be appropriate to the glucose stimulation.…”

“…With 15-to 30-min sampling intervals, the samples may capture concentrations anywhere on the curve from peak to trough. Additionally, the absorption of a meal is not a smooth process but instead occurs in a rhythmic pattern induced by the migrating myoelectric complex (9,45). This has been observed to entrain insulin secretion (45).…”

Multifaceted interplay among mediators and regulators of intestinal glucose absorption: potential impacts on diabetes research and treatment

“…In line with these findings, intestinal motility has been shown to correlate positively with intestinal absorption across the intestinal BBM (128,143). Enhanced intestinal motility promotes glucose delivery to BBM transporters by increasing the intestine's functional surface area as well as unsettling the static water layer in the intestine (121,167). Hence, thus far, the evidence supports Cholecystokinin.…”

Stimulation of small intestinal burst activity in the postprandial state differentially affects lipid and glucose absorption in healthy adult humans

“…Studies in animal models have produced conflicting results, reporting both increases (7,24) and decreases (26,29) in the absorption of glucose during interdigestive phase III activity. This discrepancy may reflect methodological differences, such as in the animal species studied (24,29), the way in which absorption was assessed (7,29), or whether the study was performed under fasting or fed conditions (24,29). A recent study in humans (34) showed a positive association between the rate of glucose absorption and duodenojejunal pressure wave frequency; however, absorption was unaffected by treatment with cisapride.…”

“…These results show that an interruption in postprandial small intestinal motility, with migrating bursts of contractions similar to interdigestive phase III activity, reduces the rate of lipid absorption, although glucose absorption is unaffected. Previous studies on the effect of phase III activity on nutrient absorption (7,24,26,29) have been limited to the assessment of glucose absorption in animal models and have yielded conflicting results. In the present study, the concurrent absorption of lipid and glucose was assessed in healthy human subjects, where mucosal dysfunction is not an issue.…”