Malnutrition significantly prolongs the delay in gastric emptying in rats

Metabolic effects of chronic starvation and malnutrition have been well characterized. Studies on the effects of malnutrition on the gastric emptying process are, however, sparse. To investigate the effect of malnutrition on gastric emptying, young, growing rats were subjected to a 65% energy restriction (fed 35% of ad libitum energy intake) for 4 weeks and their growth rate and gastric emptying time were compared with those of well nourished rats. Gastric emptying was denoted by the half-maximal emptying time (T_1/2) of either water or a 3 Kcal meal; water or meal was mixed with Tc99m-Sn-DTPA to determine T_1/2 by gastric scintigraphy method in conscious rats. Malnourished rats exhibited a depressed growth rate (0.6±0.1 g/day) when compared with that of free-feeding rats (4.0±0.3 g/day). The T_1/2 values for either water or 3 Kcal meal were significantly higher in malnourished rats when compared with those obtained with normal rats. This suggests that malnutrition significantly prolongs gastric emptying. The gastric emptying profile in rats switched from energy restriction to free-feeding regimen was similar to that of normal rats. This further emphasizes the role of nutrition in the regulation of gastric emptying.