The effects of endocrine disrupting chemicals and genetic susceptibility on male infertility

Abstract

Reproductive functions in men are impaired by many environmental, physiologic, and genetic factors. Xenobiotics (e.g. phthalate, alkylphenols, heavy metals, bisphenol A, ets) are the majority of the environmental factors which happen adverse effects with covalent interactions between intermediate metabolites and cellular macromolecules. The recent publications regarding infertility have stated that the substances do not only interfere human's normal hormone functions, but also cause the reproductive disorders such as testicular germ line cancer and prostate hyperplasia. The xenobiotics disrupting endocrine system are metabolized by the enzyme involved phase I (e.g., CYP450) and II (e.g., NAT, SULT) enzymes. Most of the enzymes are polymorphic and genetic variants modify the enzyme catalytic activities. Thus, the effects of endocrine disrupting chemicals might vary between individuals. To date, the impact of genetic variability in the capacity of metabolizing xenobiotics has not been extensively studied on male reproductive functions. The relation between environmental and genetic factors and infertility has not been shown clearly. Therefore, we aimed to evaluate the interaction between endocrine disruptors' exposure and polymorphisms involved in genes (e.g., DAZL, MTHFR, POLG) in male infertility risk by data obtained from previously studies.