Intestinal morphology and transport after ileal resection in rat is modified by dietary fatty acids

Abstract

The authors tested the hypothesis that the intestinal morphology and uptake of nutrients after resection of the distal half of the small intestine of rats responds to alterations in the dietary content of saturated (SFA) and polyunsaturated (PUFA) fatty acids. Adult female Sprague-Dawley rats were subjected to a sham operation or to the surgical resection of the distal half of the small intestine, leaving the ileocecal valve intact. The animals were fed chow for 3 weeks, then either chow or isocaloric semisynthetic SFA or PUFA diets for a further 2 weeks. Food consumption, weight gain and jejunal mucosal surface area were unchanged after ileal resection. A microdensitometric autoradiographic technique was used to examine the distribution of 3H-leucine and 3H-lysine along the villus: approximately 70% of uptake occurred in the upper 30% of the enterocytes of the villus in chow-fed rats, and this portion was unchanged by ileal resection. The jejunal uptake of 40 mM of glucose, observed in vitro, was twice as high in animals that had undergone resection and were fed SFA than in those fed PUFA. In summary, (1) there is a separation between the adaptation of intestinal transport function and dynamic/static morphology after ileal resection, and (2) glucose uptake after ileal resection is enhanced by SFA in the diet and is not explained by any changes in the animals' food intake, weight gain or intestinal morphology.