Assessment of testicular toxicity in laboratory animals.

The currently available methods of assessing testicular toxicity and fertility are discussed. Compounds inducing testicular atrophy mainly affect the seminiferous epithelium, with progressive loss of spermatozoa, spermatids, spermatocytes, and spermatogonia. Quantitative histometric analysis of spermatogenesis, together with hormone assays, could be used to advantage in defining the underlying mechanisms of toxicity.