Benefits of caloric restriction in the myenteric neuronal plasticity in aging rats.

Aging is a biologic process characterized by progressive damage of structures and functions of organic systems. In gastrointestinal tract, it can involve enteric nervous system, which plays an important role in digestion and absorption of nutrients, causing hastening of intestinal transit thus reducing its absorptive function. Caloric restriction has been used in several studies with the intention of delaying deleterious effects of aging. This study aimed to evaluate the effects of caloric restriction on myenteric neurons of ileum by aging in rats. 30 Wistar rats were grouped as follows: GI (animals aged 6 months fed with normal diet), GII (animals aged 18 months fed with normal diet) and GIII (animals aged 18 months subject to 31% of caloric restriction). The rats of the GI group were euthanized at 6 months of age and after experimental period of 12 months animals of the group GII and GIII were euthanized, the ileum of all groups were collected, measured and processed by NADPH-dp and Acetylcholinesterase. Quantitative analysis of neurons revealed that aging promotes the increasing of myenteric neurons NADPH-dp and reduces Acetylcholinesterase neuronal population. However, in the cellular profile area, were not observed significant differences between the groups. The caloric restriction has been efficient and can be used preventively because it minimizes quantitative changes associated with aging on ileum myenteric plexuses.

Morphological effects of autoclaved diet on the myenteric neurons of rats.

AIM: To evaluate the effect of autoclaved diet on the jejunum neurons of the myenteric plexus of rats during their growth. METHODS: The experimental groups were made up of rats going through weaning whose mothers received either an autoclaved or a non-autoclaved diet during gestation and lactation, and rats that were fed the same diet as their mothers during the post-weaning period. In order to measure the neurons' body profile and to quantify the number of neurons per area, preparations were stained by the nicotinamide adenine dinucleotide-diaphorase method. RESULTS: No significant changes were observed in rats' body weight or in the number of neurons regardless of the diet used (P > 0.05). There was a decrease in the jejunum-ileum length in rats treated with an autoclaved diet (P < 0.05). An increase in the neuronal cross-sectional area was seen in rats that had received the autoclaved diet, an effect that was significant for animals undergoing weaning. In addition, all observed factors showed significant differences when related to the age of the animals. CONCLUSION: The autoclaved diet did not alter the quantity of neurons, but increased their cell body area, suggesting changes similar to those observed in protein deficiency.