HUMAN GASTRIN AND VASOACTIVE INTESTINAL POLYPEPTIDE RESPONSES TO ENDURANCE RUNNING IN RELATION TO TRAINING STATUS AND FLUID INGESTED

1. Plasma concentrations of gastrin, glucose, vasoactive intestinal po lypeptide and non-esterified fatty acid were analysed in six male endu rance runners and six male hockey players before, during and 15 min af ter 90 min treadmill running at 65% maximum oxygen uptake under two co nditions: no fluid ingestion (trial A) and ingestion of 8% maltodextri n solution (trial B). 2. Exercise resulted in significantly elevated p lasma gastrin concentrations compared with resting values in both grou ps after trial A (endurance runners, 69.4ng/l; hockey players 71.4ng/l ) and trial B (endurance runners, 105.5ng/l; hockey players, 83.2ng/l) . The gastrin response was not significantly different between the tri als. 3. Plasma vasoactive intestinal polypeptide levels increased sign ificantly beyond resting levels for both groups during trial A (endura nce runners, 76.1 +/- 53.7ng/l; hockey players 155.6 +/- 41.9ng/l) and trial B (endurance runners 47.5 +/- 21.3ng/l; hockey players 132.9 +/ - 43.9ng/l). The vasoactive intestinal polypeptide response to trial B was significantly attenuated compared with trial A. 4. There were no significant differences between endurance runners and hockey players f or plasma gastrin, although hockey players produced significantly elev ated concentrations of plasma vasoactive intestinal polypeptide after both trials compared with endurance runners. 5. Plasma glucose levels throughout trial B were significantly greater than after trial A irres pective of the group. Plasma glucose concentrations were not significa ntly different between endurance runners and hockey players. 6. Plasma non-esterified fatty acid concentrations rose significantly for both groups throughout exercise. Trial B resulted in an attenuated non-este rified fatty acid response compared with trial A. 7. No significant re lationships were identifed between metabolite and gastrointestinal hor mone concentrations, or between maximum oxygen uptake and the hormonal response to exercise. 8. These results highlight the attenuating role of carbohydrate fluid ingestion and level of aerobic fitness in the r esponses of plasma vasoactive intestinal polypeptide during prolonged exercise, whereas plasma gastrin is not significantly affected by eith er.