Effect of l-glutamine on myenteric neuron and of the mucous of the ileum of diabetic rats.

The objective of this work was to investigate the effect of the L-glutamine supplementation to prevent - diabetes induced changes in myenteric neurons and also to verify the effect on the mucosa of the ileum of Wistar rats. The animals were divided in five groups (n = 5): untreated normoglycaemic (UN), normoglycaemic treated with L-glutamine (NG), untreated diabetics (UD), diabetics treated with L-glutamine, starting on the 4th (DG4) or 45th day following diabetes induction (DG45). The amino acid was added to the diet at 1%. The density and size of neurons, the metaphasic index in the crypt, the height of the villus, the depth of the crypt and the number of globet cells were determined. There was no difference in the neuronal density and in the cellular body area of the myosin-stained myenteric neurons of groups DG4 and DG45 when compared to group D. The metaphase index and the number of goblet cells showed no significant differences when all groups were compared (P > 0.05). The villi height of groups DG4 and DG45 were 45.5% (P < 0.05) and 32.4% (P > 0.05) higher than those in group UD, respectively. The analyzed crypts showed similar depth for all studied groups.

Vitamin E (α-tocopherol) supplementation enhances nitric oxide production in penile tissue of diabetic rats.

OBJECTIVE: To investigate the effects of 0.1% and 2% vitamin E (α-tocopherol) supplementation on the expression of nitric oxide (NO) in penile tissue of rats with experimentally induced diabetes mellitus (DM). MATERIALS AND METHODS: In all, 30 male rats were divided into six groups: normoglycaemic (NG), NG treated with 0.1% vitamin E (NGE1), NG treated with 2% vitamin E (NGE2), DM, DM treated with 0.1% vitamin E (DME1), and DM treated with 2% vitamin E (DME2). After 120 days the rats were killed, and penile tissue was collected and processed for neuronal NO synthase (nNOS) immunohistochemistry to determine areas of nNOS-immunoreactive varicosities. RESULTS: nNOS-immunoreactive varicosities in DME2 rats were similar to those of controls (NG) and controls supplemented with vitamin E (NGE1 and NGE2). Varicosity sizes in the NGE1 group were similar to the DM rats with no vitamin E supplementation. CONCLUSION: Supplementation with 2% vitamin E had a positive effect on areas of nNOS-immunoreactive varicosities of penile tissue in DM rats.

Vitamin E (alpha-tocopherol) supplementation in diabetic rats: effects on the proximal colon.

BACKGROUND: Neuropathy is one of the complications caused by diabetes mellitus which is directly related to the gastrointestinal manifestations of the disease. Antioxidant substances, such as vitamin E, may play an important role in the reduction of the neurological damage caused by diabetes mellitus. The aim of the present study was to determine whether vitamin E (alpha-tocopherol) at different concentrations induces any effects on the morphology of the intestinal wall and intrinsic innervation in the proximal colon of diabetic rats. METHODS: Thirty rats (90-day-old) were assigned to the following groups: N (normoglycemic), NE1 (normoglycemic supplemented with vitamin E 0.1%), NE2 (normoglycemic supplemented with vitamin E 2%), D (diabetic), DE1 (diabetic supplemented with vitamin E 0.1%), and DE2 (diabetic supplemented with vitamin E 2%). Animals received vitamin E supplementation for 120 days and were sacrificed when they were 210 days old. The proximal colon of each animal was subjected to histology to study the intestinal wall and goblet cells and processed for whole-mount preparations to morphoquantitatively determine the total myenteric population. RESULTS: Supplementation with vitamin E significantly reduced glycemia and glycated hemoglobin values and preserved the number of myenteric neurons in group DE2, without affecting intestinal area or thickness of the intestinal wall or muscular tunic. CONCLUSION: Vitamin E (2%) influenced the glycemic parameters and had a neuroprotective effect on the total myenteric population, but the morphometric characteristics of the intestinal wall were unaffected.