Low intensity exercise increased plasma gastrin and gastric acid secretion

We investigated the effect of exercise at different intensities on gastroin testinal exocrine secretion in rats. Rats were forced to run for 30 min at 15 m/min (IOW intensity exercise), 35 m/min thigh intensity exercise), or r emained on a stationary treadmill for 30 min (control). The rats were sacri ficed immediately after treadmill task. The plasma levels of gastrin, CCK, noradrenaline, and adrenaline, gastric acid content, and amylase and trypsi n contents in the small intestinal lumen, were determined. The low intensit y exercise significantly increased plasma levels of gastrin and adrenaline, gastric acid content, and amylase content in the small intestinal lumen, w hile the plasma levels of noradrenaline and of CCK were not changed. To elu cidate the role of gastrin for the increase in gastric acid content and lum inal amylase content, a specific gastrin receptor antagonist YM-022 was adm inistered 1 h prior to exercise. Administration of YM-023 completely abolis hed these increases produced by the low intensity exercise. High intensity exercise significantly increased the plasma levels of noradrenaline and adr enaline, however, no significant increase in the plasma gastrin concentrati on or gastric acid content was observed. In conclusion, low, but not high, intensity exercise stimulated gastrin release, resulting in the increases i n gastric acid and digestive enzyme contents.