Influence of blood glucose levels on rat liquid gastric emptying

The glycemic influence on liquid gastric emptying in rats was studied. Diabetic hyperglycemia was induced by streptozotocin-treated rats further received a daily insulin injection ( 2.5 or 10 IU/kg). Immediate hyperglycemia was induced in a separate group of rats by continuous intravenous glucose infusion (44 or 88 mg/kg/min) 10 min before the experiment. Rats were killed 15 min after radiochromium feeding; then the radioactivity of stomach and small intestine were counted to obtain the gastric emptying value. Emptying in diabetic rats was delayed compared with controls (mean +/- SE: 40.9 +/- 2.6% vs. 54.2 +/- 2.8%, P < 0.01). Low-dose insulin treatment reversed the impairment, while high-dose treatment even enhanced emptying. Immediate hyperglycemia induced with two glucose infusions also inhibited gastric emptying. Present results indicate that hyperglycemia elicited with any hyperglycemic model is at least one of the important mechanisms to delay liquid gastric emptying.