Vascular effects of environmental oestrogens: implications for reproductive and vascular health

Environmental oestrogens are defined as xenobiotics structurally resembling oestrogen, and are divided into two broad categories, xeno-oestrogens and phyto-oestrogens. Environmental oestrogens may contribute importantly to the increased incidence of reproductive disorders in the modern environment. Although the mechanisms by which environmental oestrogens induce their deleterious effects on the reproductive system remain poorly defined, it is likely that the vascular effects of these compounds play a critical role. In this regard, oestradiol strongly regulates both angiogenesis and vascular remodelling by influencing the growth and function of vascular endothelial cells (EC) and smooth muscle cells (SMC). Since blood vessels, by undergoing angiogenesis, vascular regression and vascular remodelling, actively participate in the normal functioning of reproductive organs, environmental oestrogens-by mimicking or antagonizing the vascular effects of oestradiol-may induce abnormalities in vascular function and structure leading to reproductive disorders such as pre-eclampsia, endometriosis, impaired follicular development, inefficient implantation, impotence and infertility. The purpose of the present review is to summarize the evidence regarding the vascular effects of xeno-oestrogens and phyto-oestrogens and to discuss the implications for these effects on the reproductive system.