The impact of metalloestrogens on the physiology of male reproductive health as a current problem of the XXI century

Abstract

In the XXI^st century in highly developed countries, progressively decreasing male reproductive potential is indicated. In recent years epidemiological studies indicate the deterioration of semen parameters: reduction of ejaculate volume, sperm count, and mobility, as well as abnormalities in their morphology. Male infertility can result from many different agents, such as: anatomical or genetic abnormalities, systemic or neurological diseases, infections, trauma, iatrogenic injury, gonadotoxins and development of sperm antibodies and lifestyle (especially obesity, heat and tobacco smoking). It is well documented that adverse changes in male fertility also seem to be associated with environmental exposure to different substances, especially endocrine active factors, known as xenoestrogens, and among these metal ions, known as metalloestrogens, are very important. The role of some metalloestrogens in various diseases, both in women and men, is known and particularly well-proven in women, but still little is known about their role in the regulation of male reproductive potential. Thus we decided to analyse the available information exploring this problem. The review was carried out using the Medline and Google Scholar databases, using the keywords: xenoestrogens, metalloestrogens, male fertility, semen quality, male reproductive potential, mechanisms of metalloestrogen action, environmental pollution and the name of the particular metal. Articles published between 2000 - 2019 have been taken into account, including human and vertebrate animal studies and cell lines. The aim of this review is to discuss the role and mechanisms of action of fifteen metalloestrogens in the human organism, as well as in animal models, and cell cultures, paying special attention to their influence on the physiology of male reproductive health, according to the current state of knowledge. The role of certain metals in human reproduction is still poorly investigated and for some of them only single studies are available. Many factors in our daily lives have a significant impact on male fertility, therefore education is necessary on the threats and how they may be eliminated as far as possible.