Semen characteristics and serum and seminal plasma hormones in drug-induced hyperprolactinaemia.

Semen volume, density, motility, viability, and morphology of spermatozoa, and serum and seminal plasma levels of the hormones FSH, LH, prolactin, progesterone, 17-alpha-hydroxyprogesterone, androstenedione, testosterone, dihidrotestosterone, and estradiol 17-beta have been measured in 22 men subjected to experimental hyperprolactinaemia by the simultaneous administration of the antidopaminergic drugs metoclopramide and sulpiride. Hyperprolactinaemia produces a decrease of semen volume and seminal quality. In hyperprolactinaemia, normozoospermic patients had an increase of serum androstenedione. In both normo- and oligozoospermic groups, a decrease of serum testosterone was observed. Hyperprolactinaemia also causes an inhibition of the secretory activity of the accessory sexual glands of the reproductive tract, as well as either a decrease of 17-ketosteroid reductase or an increase of 17-alpha-hydroxysteroid dehydrogenase (enzymes that participate in the androstenedione-testosterone interconversions). This change appears to be more pronounced in individuals with good seminal quality.