Influence of forced treadmill and voluntary wheel running on the sensitivity of gastric mucosa to ulcerogenic stimuli in male rats.

Physical activity is crucial for maintaining health. Here we investigated the preconditioning effects of exercise on the vulnerability of gastric mucosa to ulcerogenic action of indomethacin (IM, 35 mg/kg, s.c.) or cold-restraint stressor (CR, 3 h, 10°C) in male rats. Single or repeated (5 days) training was used either voluntarily (2 h/day, wheel running) or in a forced way (treadmill). The intensity of the later was either "moderate" (9 m/min, 15 min) or "intensive" (15 m/min, 30 min). All protocols were confirmed by elevated plasma corticosterone and increased tail flick latencies (analgesia). IM-induced ulceration was attenuated by single intensive forced exercise, repeated voluntary and moderate forced exercise. On the contrary, single 2 h voluntary session aggravated the IM-induced ulceration. The ulcerogenic effect of CR was aggravated by single and repeated voluntary and single intensive forced exercise, while repeated moderate forced running was gastroprotective. Single moderate forced running did not influence the ulcerogenic effect of both agents. The results suggest that physical training might have both beneficial and harmful effects on the vulnerability of gastric mucosa to ulcerogenic stimuli depending on the nature of ulcerogenic stimulus as well as the intensity of running and its duration.