Acetylsalicylic acid inhibits the pituitary response to exercise-related stress in humans

Purpose: Prostaglandins (PGS) modulate the activity of the hypothalamus-pit uitary axis, and pituitary hormones are largely involved in the physiologic al responses to exercise. The purpose of this study was to analyze the effe cts of acetylsalicylic acid (ASA), an inhibitor of PGs synthesis, in the pi tuitary responses to physical stress in humans. Methods: Adrenocorticotropi n (ACTH), beta -endorphin, cortisol, growth hormone (GH), and prolactin (PR L) responses to exercise were evaluated after administration of either plac ebo or ASA. Blood samples for hormone evaluations before (-30, -15, and 0 p re) and after (0 post, +15, +30, +45, +60, and +90 min) a 30-min treadmill exercise (75% of (V) over dot O-2max) were taken from 12 male athletes duri ng two exercise trials. One tablet of ASA (800 mg), or placebo, was adminis tered two times daily for 3 d before and on the morning of each exercise-te st. Results: The results clearly show that, compared with placebo, ASA inge stion significantly blunted the increased serum ACTH, beta -endorphin, cort isol, and GH levels before exercise (anticipatory response) and was associa ted with reduced cortisol concentrations after exercise. Furthermore, altho ugh no differences in the GH response to exercise were shown, a significant ly reduced total PRL response to stress condition was observed after ASA. C onclusion: ASA influences ACTH, beta -endorphin, cortisol, GH, and PRL resp onses to exercise-related stress in humans (preexercise activation/exercise -linked response). Even though it is not possible to exclude direct action for ASA, our data indirectly confirm a role of PGs in these responses. We h ave to further evaluate the nature of the preexercise endocrine activation and, because of the large use of anti-inflammatory drugs in athletes, wheth er the interaction between ASA and hormones might positively or negatively influence health status, performance, and/or recovery.