EFFECT OF EXERCISE INTENSITY ON PLASMA PROSTAGLANDIN CONCENTRATIONS IN HORSES

Exertion has an effect on plasma, serum, and/or urine prostanoid conce ntrations in many species, We investigated the effect of exercise inte nsity on plasma prostaglandin concentrations during and after exercise in horses. Six Thoroughbreds completed 4 trials: 3 exercise trials (l ow-, medium-, and high-speed) and 1 nonexercise (control) trial on a h igh-speed treadmill, Blood samples were collected from a jugular cathe ter before, during, and after exercise. The pcv and blood lactate, pla sma protein, plasma prostacyclin (6-keto-PGF(1 alpha)), thromboxane B- 2 (TXB(2)), and prostaglandin E(2) (PGE(2)) concentrations were measur ed before, during and after exercise. Exercise significantly (P = 0.00 1) increased plasma TXB(2) concentration during and after exercise in the low-, medium-, and high-speed trials, although effect of exercise intensity was not detected. Exercise was associated with an increase i n PCV and blood lactate and plasma protein concentrations, There was n o effect of exercise on plasma 6-keto-PGF(1 alpha), concentrations; PG E(2) was not detected in plasma from any horse in any trial.