RESUMO
AIM: To investigate the effect of acute exhaustive exercise on gastrointestinal motility and its enteric nervous mechanisms. METHODS: 24 rats were randomly divided into control group (C) and acute exhaustive exercise group (AEE). The rate of gastrointestinal transit was measured and histologic changes of nitriergic nerves in ileum myenteric plexus were observed with enzymatic histochemical and image analytic technique. RESULTS: In the rats of AEE group, the rate of gastrointestinal transit was delayed comparing with C group (P < 0.05), the numbers of nitrergic neurons and expression levels of nitric oxide synthase (NOS) in the ileum myenteric plexus significantly increased comparing with C group (P < 0.01). CONCLUSION: It is possible that increase of nitrergic neurons and expression levels of NOS in the myenteric plexus of small intestine are one of the mechanisms of delay of gastrointestinal transit rate in acute exhaustive exercise rats.