Prolactin release induced by physical exercise is independent from peripheral vasoactive intestinal polypeptide secretion.

The plasma concentrations of vasoactive intestinal polypeptide and prolactin were measured before and after an exhaustive and a submaximal exercise test in 7 male marathon runners. A significant increase of vasoactive intestinal polypeptide was recorded after both tests, whereas the prolactin increase was observed only after the exhaustive exercise test. No significant correlation was found between the plasma vasoactive intestinal polypeptide and the plasma prolactin values recorded during the two exercise tests. Data suggest that the exercise-induced prolactin release occurs independently from variations of the vasoactive intestinal polypeptide levels in peripheral circulation.