The present study evaluated the effects of supplementation with a combination of vitamin C and vitamin E on NADH-diaphorase-positive (NADH-d+) and neuronal nitric oxide synthase (nNOS)-immunoreactive myenteric neurons in the duodenum and ileum in diabetic rats. Forty rats were distributed into the following groups: normoglycemic (N), normoglycemic supplemented with vitamin C and vitamin E (NS), diabetic (D), and diabetic supplemented with vitamin C and vitamin E (DS). Vitamin C was added to the drinking water, and vitamin E was incorporated in the diet (1%). After 120 days, the animals were euthanized, and the duodenum and ileum were subjected to NADH-d and nNOS staining. Quantitative and morphometric analyses of myenteric neurons were performed. Diabetes reduced NADH-d+ neurons in the D group. The density of nitrergic neurons was not changed by diabetes or vitamin treatment. Hypertrophy of the cell body area of NADH-d+ and nNOS-immunoreactive neurons was observed in both intestinal segments. Combined supplementation with vitamin C and vitamin E prevented the reduction of the density of NADH-d+ neurons and hypertrophy, demonstratred by both techniques. Supplementation with a combination of vitamin C and vitamin E promoted myenteric neuroprotection in the small intestine in diabetic rats.
ascorbic acid; α-tocopherol; diabetes mellitus; myenteric plexus; enteric nervous system
