Concentrations of intracellular sex steroids in human spermatozoa

In an attempt to determine whether human spermatozoa contain steroid hormones, the immunoreactive levels of progesterone, testosterone, and estradiol-17 beta were measured in the extracts of sonicated specimens of sperm obtained as ejaculates from husbands of infertile couples (n = 67, age 26-44 years). In the range of sperm concentration between 3.0 and 869.6 million per ejaculate (143.2 +/- 13.6 mean +/- SEM), the concentrations were as follows: progesterone 127.3-6685.4 fmol/ml (1434.5 +/- 178.6), testosterone 98.3-2219.1 fmol/ml (611.6 +/- 49.0), and estradiol-17 beta 33.0-678.1 fmol/ml (206.9 +/- 19.7). Using Pearson's correlation coefficient, the steroid hormone levels correlated significantly with the total sperm number (p < .02). The spermatozoa contained small but measurable amounts of the sex steroids.