Efeitos do exercício sobre o envelhecimento dos neurônios mioentéricos do duodeno de ratos Wistar / Effects of the exercise on the ageing of the myenteric neurons in the duodenum of Wistar rats

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

With ageing, there is an increase in the incidence of gastrointestinal problems related to intestinal motility. Physical activity may promote significant functional alterations, acting to minimize the deleterious effects of the ageing process. The control of gastrointestinal functions is carried out by the enteric nervous system, composed of a network of intramural neurons. However, nothing is known about the effects of regular physical activity on the ageing of myenteric neurons. Therefore, the object of this study was to analyze the quantitative and morphological alterations caused by ageing and physical activity on the NADH and NADPH-diaphorase positive myenteric neurons in the duodenum of middle-aged rats and, furthermore, to verify, through light and transmission electron microscopy, any alterations in the morphology and ultrastructure of the plexus and the thickness of the muscular tunica. To this end, 45 Wistar rats were divided into three groups: group C (six months old - sedentary), group S (twelve months old - sedentary) and group T (twelve months old - submitted to physical activity). The animals of group T underwent physical activity five times a week for six months. No morphological alteration was found among the groups. However, it was found that the basal membrane had a stronger outline and collagen fibers were more grouped in the ganglia of the animals of groups C and T, compared to those of group S. In the quantitative analysis, a reduction in NADPH-diaphorase positive neurons with ageing and with the practice of physical exercise was observed. There was also a decrease in NADH-diaphorase positive neurons with ageing, although there was a slight increase with physical activity (P>0.05). No significant alteration was observed in the area of the neuronal profiles of the NADPH and NADH-diaphorase positive neurons with ageing (P>0.05). With regards to physical activity, a significant reduction in cellular profile area was only found in the NADPH-diaphorase positive neurons. No significant alteration was found in the thickness of the muscular layer of the duodenum (P>0.05). Key words: Myenteric plexus, ageing, physical activity.

ASSUNTO(S)

atividade física envelhecimento physical activity myenteric plexus ageing plexo mioentérico

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