Figure 1.

Mean estradiol concentration during 24-hours secretion. Concentrations below the detection limit (patterned area) during 24-hour sampling were set to the expected value of 2 pmol/L. A. Mean estradiol during 24 hours from 62 serum profiles. The bars show the median for the estradiol level in each pubertal group. B. Mean estradiol during 24 hours serum profiles in samples from 8 boys who have been followed-up with repeated estradiol measurements during pubertal development.