Investigation of antioxidative capacity in bovine seminal plasma. Effects of Omega-3 fatty acids

Doktorarbeit / Dissertation , 2010 , 87 Seiten

Tiermedizin / Veterinärmedizin

Bovine semen has been cryopreserved since more than a half century for artificial insemination and nowadays it is being widely used all over the world. However, it is well known that the cryopreservation procedure is detrimental to sperm particularly because of chemical and physical stress factors which are occurring during this process. One important factor is oxidative stress which, in turn, affects biological membranes and DNA of sperm. Bovine sperm themselves have only few amounts of endogenous antioxidants for the protection against reactive oxygen species (ROS) and the main antioxidant source is the seminal plasma. Therefore, the development of sensitive techniques for monitoring the activity of antioxidants in seminal plasma is of clinical importance. Sensitive chemiluminescence techniques have been employed to monitor total antioxidant capacity of human seminal fluid.

Polyunsaturated fatty acids (PUFA) play an important role in regulating sperm membrane fluidity and spermatogenesis. After freezing and thawing, the portion of PUFA in sperm plasma membrane decreases significantly due to lipid peroxidation. Low portions of C20 and C22 PUFAs in sperm in old bulls were related to reductions in sperm quality and -fertilizing ability.

In various feeding experiments polyunsaturated fatty acids (PUFA) have been supplied to change the fatty acid composition of sperm membrane in order to improve sperm quality and fertility. Indeed, the fatty acid profile of sperm membranes can be modified with diet and an improvement of sperm quality was observed in a variety of livestock species including chicken, turkey, boar and stallion. However, it is possible that feeding of PUFAs reduces also the antioxidative capacity of semen which, in turn, can disturb sperm quality in the case of excessive ROS production.

The aims of this study are: (i) to determine total antioxidant capacity of bovine seminal plasma and its relationship with other antioxidants and sperm quality; (ii) to ascertain whether feeding omega-3-fatty acid reduces the antioxidative status of seminal plasma.

Inhaltsverzeichnis (Table of Contents)

• 1 INTRODUCTION
• 2 REVIEW OF LITERATURE
  • 2.1 Reactive Oxygen Species
    • 2.1.1 Definition and existence of reactive oxygen species
    • 2.1.2 Oxidative stress
    • 2.1.3 Significance of oxidative stress in male reproduction
      • 2.1.3.1 Sources of ROS in semen
      • 2.1.3.2 Targets and pathological role of ROS in semen
        • Lipids of sperm plasma membrane and lipid peroxidation
        • Damage of DNA
        • Damage of proteins
        • Apoptosis
      • 2.1.3.3 Physiological role of ROS in semen
  • 2.2 Antioxidants
    • 2.2.1 Enzymatic antioxidants
      • 2.2.1.1 Superoxide dismutase
      • 2.2.1.2 Glutathione Peroxidase
      • 2.2.1.3 Catalase
    • 2.2.2 Non-enzymatic antioxidants
  • 2.3 Seminal plasma and its antioxidative significance for male reproduction
    • 2.3.1 Accessory glands and seminal plasma
    • 2.3.2 Antioxidative properties of seminal plasma
  • 2.4 Measurement of oxidative stress and antioxidants using chemiluminescence
• 3 OWN EXPERIMENTAL STUDIES
  • 3.1 Establishment of a new assay for the determination of total antioxidative capacity of bovine seminal plasma
    • 3.1.1 Abstract
    • 3.1.2 Introduction
    • 3.1.3 Materials and Methods
      • 3.1.3.1 Chemicals
      • 3.1.3.2 Semen collection, dilution and freezing
      • 3.1.3.3 Handling of seminal plasma

Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)

This dissertation investigates the antioxidative capacity of bovine seminal plasma and the effects of Omega-3 fatty acids on this capacity. The study aims to establish a new assay for the determination of total antioxidative capacity in bovine seminal plasma and analyze the impact of Omega-3 fatty acids on this parameter. Key themes explored in this work include:

• Reactive oxygen species (ROS) and their role in male reproduction
• Antioxidant systems in bovine seminal plasma
• The impact of Omega-3 fatty acids on antioxidative capacity
• Development of a new assay for measuring total antioxidative capacity
• The importance of oxidative stress in male reproductive health

Zusammenfassung der Kapitel (Chapter Summaries)

* **Chapter 1: Introduction:** This chapter provides a general overview of the topic and outlines the research questions and objectives of the dissertation. * **Chapter 2: Review of Literature:** This chapter provides a comprehensive review of the current scientific literature on reactive oxygen species, antioxidants, and their significance in male reproduction, focusing particularly on bovine seminal plasma. It covers the definition and existence of reactive oxygen species, oxidative stress, its sources and targets in semen, as well as the physiological role of ROS in semen. The chapter also discusses enzymatic and non-enzymatic antioxidants, including superoxide dismutase, glutathione peroxidase, catalase, and other non-enzymatic antioxidants. Additionally, it explores the composition and antioxidative properties of seminal plasma. * **Chapter 3: Own Experimental Studies:** This chapter details the author's own research, specifically focusing on the development of a new assay to measure the total antioxidative capacity of bovine seminal plasma. It outlines the materials and methods used, including the collection, dilution, and handling of semen and seminal plasma, as well as the chemical reagents employed.

Schlüsselwörter (Keywords)

This dissertation focuses on the key areas of bovine reproduction, oxidative stress, antioxidants, seminal plasma, Omega-3 fatty acids, and the development of a new assay to measure total antioxidative capacity. The study emphasizes the importance of understanding the role of oxidative stress in male reproductive health and the potential benefits of Omega-3 fatty acids in mitigating oxidative damage.

• Autor: Oğuz Çalışıcı (Autor:in)
• Erscheinungsjahr: 2010
• Seiten: 87
• Katalognummer: V385556
• ISBN (eBook): 9783668604124
• ISBN (Buch): 9783668604131
• Sprache: Englisch
• Schlagworte: investigation, effects, omega-3, bovine, seminal plasma, sperm, fatty acids, cyropreservation