Eva Tvrdá

By Tomáš Jambor, Bistáková Jana, Greifová Hana, Tvrdá Eva and Lukáč Norbert

Infertility is a major health issue affecting human life. The most notable factors causing male infertility is exposure to environmental contaminants. Bisphenol A (BPA) is a common toxic environmental contaminant. Human population is exposed to bisphenol A through air, water, food and a variety of industrial products. Growing evidence from research on laboratory animals supports the hypothesis that bisphenol A is able to adversely affect male reproductive function. The specific mechanisms of action of bisphenol A are wide but not definite. Bisphenol A interferes with the hormonal metabolism and regulation, binding affinity or enzymatic activity, resulting in a deviation from a normal reproductive behaviour. Binding ability to androgen and oestrogen receptors, as well as other properties, is currently investigated. A decreased sperm count, inhibition of sperm motility and reduction of organ weights were observed and linked with oxidative stress after bisphenol A treatment. In addition, prenatal exposure to bisphenol A may lead to adverse effects in the offspring. In this review, we address the topic of BPA effects on male reproductive function and emphasize its effects on testicular steroidogenesis and spermatogenesis. A considerably more detailed and systematic research focusing on bisphenol A toxicology is required for a better understanding of risks associated with exposure to this endocrine disruptor.

Part of the book: Bisphenol A

By Eva Tvrdá, Peter Massanyi and Norbert Lukáč

Oxidative stress (OS) is a condition caused by an imbalance between reactive oxygen species (ROS) overgeneration and decreased antioxidant defense mechanisms in the cell. OS has become a prominent factor in male reproductive dysfunction as ROS cause damage to sperm DNA, lipids and proteins, alterations to critical sperm structures and signaling pathways, leading to a decreased sperm activity and fertilizing capacity. At the same time, small amounts of ROS play vital roles in events leading to sperm maturation and acquisition of functional activity, which is why a proper oxidative balance is of paramount importance for a proper male fertility. Understanding the physiological and pathological roles of ROS in male reproduction has become an essential pillar of modern andrology; however, numerous questions related to the controversial behavior of ROS in male reproductive cells and tissues still remain unanswered. This chapter aims to summarize current evidence available on the relationships between free radicals, antioxidants and male reproduction and to trigger more scientific interest, particularly with respect to the design of efficient strategies to diagnose or treat male sub- or infertility associated with OS.

Part of the book: Spermatozoa

By Filip Benko, Mária Chomová, Oľga Uličná and Eva Tvrdá

This chapter examines the impact of diabetes mellitus type 2 (DM 2) on the vitality of male reproductive cells collected from Zucker diabetic fatty (ZDF) rats which could be a suitable experimental model for simulating this metabolic disorder. Epididymal spermatozoa were subjected to the assessment of motility, membrane integrity, mitochondrial activity, DNA fragmentation, and oxidative profile. Our results show that DM 2 in combination with obesity negatively affects the sperm vitality and increases the chances of oxidative damage to male gametes. In conclusion we may state that DM 2 has a negative impact on the spermatogenic aspect of male fertility and decreases the sperm quality.

Part of the book: Animal Models in Medicine and Biology