Responsiveness of plasma 2- and 4-hydroxycatecholestrogens to training and to graduate submaximal and maximal exercise in an untrained woman. Interuniversity Project on Reproductive Endocrinology in Women and Exercise.

ABSTRACT

A single-subject experimental design was used to obtain some preliminary findings on the plasma responses of catecholestrogens (CE) to acute exercise and brief, but exhaustive training on a cycle ergometer. One previously untrained eumenorrheic female (body fat 26% VO2max 43.3 ml x kg(-1) x min[-1]) participated in this study. Resting CE levels were for "total" (unconjugated + conjugated) 2-hydroxyestrogens (2-OHE) 162pg/ ml and 350 pg/ml in the follicular (FPh) and luteal phase (LPh), respectively. Plasma total 4-hydroxyestrogen (4-OHE) levels were 41 pg/ml in the FPh and 66 pg/ml in the LPh. For "total" 2-methoxyestrogens (2-MeOE), we found 257 pgl/ml in the FPh and 374 pg/ml in the LPh. Resting levels of 2-hydroxy CE following a period of brief, intensive training were decreased during the LPh (2-OHE -38%; 2-MeOE -19%), whereas 4-hydroxy CE were unaffected. After training, the formation of CE as expressed by the 2-OHEE and 4-OHEE ratios, was increased by 75% and 200% at rest, respectively. CE activity or O-methylation, as estimated from the 2-MeOE2-OHE ratio, was higher following training (FPh +22%; LPh +30%). During acute exercise before training, we observed a small rise proportional to the exercise intensity in the plasma "total" primary estrogen concentrations (FPh +28%; LPh +16%), and no changes in either 2-OHE or 2 MeOE levels. Plasma concentrations of 4-OHE, however, doubled during maximal exercise intensity. The 2-OHEE and 2-MeOE2-OHE ratios did not alter during incremental exercise. Training effects on acute exercise responses were only noticed for 4-OHE, which contrary to pre-training conditions, now progressively decreased. The major findings of this study are that in response to training a) during rest, a greater proportion of CE are formed from a lower amount of precursor hormone, b) the rate of O-methylation of CE increases.