Abstract

Plasma prolactin (PRL), 17-beta estradiol (E2) and progesterone of eight college-age amenorrheic (AM) and 21 endurance athletes with regular menses were determined by radioimmunoassay from blood samples taken just before and immediately following a 45 min training run. Baseline PRL was 14.4 +/- 1.4 (S.E.M.) ng/ml for the AM group and 16.4 +/- 2.1 ng/ml for the controls. Postexercise PRL was 17.3 +/- 1.8 ng/ml for the AM athletes and 46.8 +/- 7.3 ng/ml for controls, a difference which was statistically significant. Mean levels of E2 of AM subjects increased from 40 +/- 13 to 60 +/- 18 pg/ml following exercise, and from 118 +/- 23 to 182 +/- 35 pg/ml in controls. Pre-exercise and post-exercise E2 differences between AM and control athletes were statistically significant, as were the exercise-associated increases. Plasma progesterone was unaffected by exercise. The AM athletes weighed less and ran more miles weekly but were similar to the controls in all other respects. Verf.-Referat