Ovarian intrafollicular processes as a target for cigarette smoke components and selected environmental reproductive disruptors.

Steroidogenesis, expansion of oocyte-cumulus complex, and meiotic maturation of the oocyte represent intrafollicular processes taking important part in the background of successful fertilisation. The reproductive health of female could be affected by a number of endogenous as well as exogenous factors, such as exposure to agents from specific lifestyle habits, environmental pollutants with endocrine disrupting properties, or heavy metals. Published data indicate that exposure to chemicals may cause alterations in reproductive behavior and contribute to sub-fecundity, infertility, or ovarian failure. Female reproductive functions can be compromised by exposure to toxic chemicals at a variety of sites, including ovary or reproductive tract. Substantial harmful effects of cigarette smoke on fecundity and reproduction have become apparent but are not generally appreciated. The effects of cigarette smoke components (cadmium, nicotine, cotinine) absorbed into the organism on intrafollicular processes may thus in part explain the negative impact of smoking on female fertility. Moreover, it is now evident that a variety of man-made pollutants present in the environment are capable to disrupt normal endocrine function in many species. Examples of these "endocrine disrupters" include plasticizers, such as phthalates and bisphenol A. The effects of selected environmental chemicals on the processes of steroidogenesis, expansion of oocyte-cumulus complex, and meiotic maturation of the oocyte are summarized in the present paper and possible mechanisms of action of these agents are suggested. However, for complete understanding the mechanisms by which chemical agents from the environment can affect the intrafollicular processes, a lot of further investigation is needed.