Accelerated gastric emptying in diabetic rodents: effect of insulin treatment and pancreas transplantation.

Gastric emptying of a suspended solid, digestible meal was examined after 30 to 90 days of diabetes in two strains of streptozotocin-treated rodents and in genetically diabetic BB/Wor rats. After a 14-hour overnight fast the animals were gavage-fed 1.0 gm of rat food suspended in water and were killed 30 minutes later. Ligatures were placed around the lower esophageal sphincter and the pylorus and the stomachs were removed intact. The stomachs were evacuated and the gastric contents and gastric remnant were separately dried and weighted. Both the streptozotocin-treated and BB/Wor rats showed significantly accelerated (1.5- to 2.2-fold) rates of gastric emptying of the meal compared with respective nondiabetic control animals. Streptozotocin-treated diabetic animals that received daily insulin supplementation or those that had undergone pancreas transplantation shortly after induction of diabetes showed a similar reduction in blood glucose levels and normal rates of gastric emptying. Diabetes had a significant but variable effect on gastric mass and body weight. This response was dependent on the strain of animal examined, whether or not insulin supplementation was administered, or whether the animal underwent pancreas transplantation. These observations indicate that early diabetes in rodents has a prokinetic effect on gastric emptying of a suspended solid digestible meal. Restoration of euglycemia by insulin treatment or pancreas transplantation is associated with return of the gastric emptying rate to normal. These changes in gastric emptying appear to be independent of the effects of diabetes on gastric mass.