[Effect of drugs and environmental pollutants on human spermatogenesis]

Following a short description of the dynamics of spermatogenesis possible pharmacological effects are discussed. These are: 1st a directly cytotoxic effect, 2nd a peripheral endocrine effect (androgen inhibition), and 3rd a central endocrin eff (gonadotrophin inhibition). Cytostatic drugs are the substances most dangerous to the seminiferous epithelium. If the treatment period takes more than 6 months, the damage is irreversible. After shorter periods the risk of chromosomal disarrangements is enhanced in the phase of regeneration. The widespread environmental pesticides act in a similar manner. Also retinoids, sulfasalazine and heavy metals have predominantly cytotoxic effects. Hormones administered in pharmacological doses will exert endocrine effects. The clinical symptoms are mainly those of disturbed sexual function, as the lack of testosterone is visible at first in peripheral organs. Estrogens, gestagens and antiandrogens act in a similar manner, but even exogenous testosterone will inhibit the spermatogenesis.