Assessing Male Reproductive Toxicity during Drug Development

Male infertility accounts for about 50% of infertility cases [1]. Anatomic, genetic, endocrinological, environmental, behavioral and nutritional imbalances are critical causes of male infertility [2-5]. Therapeutic drugs can also adversely affect male fertility by injuring testicular cells or instigate hormonal changes that lead to decreased semen quality (Figure 1) thereby compromising the production of competent spermatozoa [6,7]. The male reproductive system is a complex and sensitive regulated process that can be disturbed following exposure to toxic compounds. Besides genetic defects, it is believed that most of male reproductive anomalies depend on exogenous toxic exposures, the so called Testicular Dysgenesis Syndrome [8].