Adaptation to physical load increases the activity of prostaglandins E and I2 and reduces stress reaction

Abstract

Adaptation to physical load protects against stress and other damage. It is suggested that this protection is associated with activation of prostaglandins E (PGE) and 12 (PGI2). Plasma contents of PGE2, PGI2, and thromboxane A 2 (TxA2) and the severity of stress reaction are measured in male Wistar rats adapted to swimming. Training increases the concentrations of these prostaglandins and the prostaglandin/TxA 2 ratio, reduces almost 2-fold the severity of stress reaction as assessed by the plasma corticosterone concentration and corticosterone/insulin ratio. After stress, the PGI 2 and PGIJTxA_, in adapted rats were, respectively, 33 and 31% higher than in unadapted. These findings suggest that prostaglandins are involved in the reduction of stress reaction.