THE PLASMA CONCENTRATION OF UNCONJUGATED OESTRONE AND 17β-OESTRADIOL DURING THE NORMAL MENSTRUAL CYCLE

Abstract

ABSTRACT By a double isotope derivative technique, the content of »free« oestrone and 17β-oestradiol was determined in plasma from normally menstruating women. Through the cycle the concentration of the two hormones was found to range from 0.1–0.3 μg/l, substantially higher values being found only in the middle third of the cycle. Daily determinations around the time of ovulation in a few women showed a short-lasting increase up to 1 μg/l. This increase appears to precede ovulation, and the authors advance the idea that this increase is a contributory cause of ovulation.