Male contraception in the preclinical evaluation

Abstract

In women the inhibition of ovulation is a successful way of excluding germ cells from fertilization. In men the function of the germ cells cannot be inhibited as easily. The close association, both morphological and functional, of spermatogenesis and androgen synthesis presents problems which have not yet been solved. The consideration of sperms as a single compartment is wrong, since libido and sperm function are closely linked together. All methods which have been developed to directly inhibit the spermatogenesis or the spermiogenesis did not produce satisfactory results. Acylating or heterocyclic substances which were effective inhibitors were too toxic in animal experiments. One such substance which affects spermatogenesis is gossypol (Figure 1). This binaphthalene isolated from cotton seeds inhibits sperm maturation.