Alterations of the Sister Chromatid Exchange frequency in peripheral lymphocytes caused by an Ironman triathlon

Diploma Thesis , 2007 , 86 Pages , Grade: 1,0

Medicine - Human Genetics

The aim of the present study was to investigate the effect of a triathlon (3.8 km swim, 180 km cycle, 42,2 km run) on the genomic stability of nine highly trained non-
professional athletes.
Therefore, the SCE assay, a relevant biological response marker for genotoxicity in
human biomonitoring studies [PENDZICH et al., 1997] was performed using peripheral
lymphocytes, on account of their effortless accessibility [WILKOSCY and RYNARD,
1990].
Duplicate lymphocyte cell cultures, of each participant, were incubated for 72 h (37°C, 5% CO2) according to a short-term human lymphocyte cell culture. For each participant at least 50 metaphases, containing 43-46 chromosomes were scored, to evaluate the mean SCE frequency. The number of SCEs per cell was calculated to a chromosome set of a normal diploid human cell, containing 46 chromosomes.
In the present study the alteration of SCE frequency, 48 h pre- and 24 h postrace was evaluated. As an additional endpoint Top 5 HFCs (highest five absolute SCE means) were assayed. It could be demonstrated that both the total mean SCE frequency and the mean Top 5 HFC frequency (n=9) 24 h postrace were significantly decreased (*p< 0.05) compared to 48 h prerace values. Considering the training status, a significant negative correlation between the relative SCE changes before and after the triathlon was observed for the cycling training per week (km) (r=-0.86; **p< 0.01), the running training per week (km) (r=-0.90; *p< 0.05)
as well as for the weekly net exercise training time (h) (r=-0.89; *p< 0.05). The relative changes of Top 5 HFCs before and after the race correlated significantly with the cycling training per week (km) (r=-0.79; *p< 0.05) and with the body mass index
(kg/m2) (r=-0.69; *p< 0.05). These findings suggest the existence of endogenous repair mechanisms which seem to prevent DNA damage.

Inhaltsverzeichnis (Table of Contents)

• 1. INTRODUCTION
• 2. BACKGROUND
  • 2.1. Human lymphocytes
  • 2.2. Cell cycle
    • 2.2.1. Interphase
      • 2.2.1.1. Checkpoints
    • 2.2.2. Mitosis
  • 2.3. Sister Chromatid Exchange
    • 2.3.1. Mechanism of SCE
    • 2.3.2. Scientific significance of the SCE assay
    • 2.3.3. SCE inducing agents
    • 2.3.4. Persistence of SCE
    • 2.3.5. Historical background
    • 2.3.6. BrdU incorporation and visualization of SCEs
    • 2.3.7. The role of cell culture components
    • 2.3.8. Factors potentially influencing SCE frequency
      • 2.3.8.1. Culture factors
      • 2.3.8.2. Biological and physiological factors
  • 2.4. The Correlation between strenuous endurance exercise and genotoxicity
    • 2.4.1. Reactive oxygen species (ROS) and physical exercise
    • 2.4.2. Exercise-induced oxidative stress
    • 2.4.3. Exercise-induced DNA damage
      • 2.4.3.1. Relation to oxygen consumption
      • 2.4.3.2. Relation to a single bout of exercise
    • 2.4.4. Exercise-induced adaptation
    • 2.4.5. Regular physical exercise
• 3. MATERIALS AND METHODS
  • 3.1. Project description
  • 3.2. Subjects
    • 3.2.1. Inclusion criteria
    • 3.2.2. Exclusion criteria
      • 3.2.2.1. Supplementation guidelines
  • 3.3 Equipment for the SCE assay
  • 3.4. Reagents of the SCE assay
    • 3.4.1. Manufacturing processes and storage of reagents for SCE assay
  • 3.5. Basic assay approach
  • 3.6. Assay description
  • 3.7. Blood collection
  • 3.8. Sister Chromatid Exchange assay
  • 3.9. Statistical analysis
  • 3.10. Guidelines for microscopic assessment
  • 3.11. Top five HFCS
• 4. RESULTS AND DISCUSSION
  • 4.1. Study design
  • 4.2. Subjects characteristics
  • 4.3. Preliminary testing
  • 4.4. Assay criteria
  • 4.5. Distribution of evaluated SCEs per cell
  • 4.6. Abs. SCES
    • 4.6.1. Descriptive statistics
    • 4.6.2. Single means of abs. SCES
    • 4.6.3. Total mean abs. SCES
  • 4.7. Top 5 HFCS
    • 4.7.1. Descriptive statistics
    • 4.7.2. Single means of Top 5 HFCs
    • 4.7.3. Total mean Top 5 HFCs
  • 4.8. Correlations
    • 4.8.1.Abs. SCES
    • 4.8.2. Top 5 HFCs
• 5. CONCLUSION
• 6. SUMMARY
• 7. ZUSAMMENFASSUNG
• 8. REFERENCES
• 9. APPENDIX
  • 9.1. Single values of participant 36
  • 9.2. Single values of participant 37
  • 9.3. Single values of participant 39
  • 9.4. Single values of participant 41
  • 9.5. Single values of participant 42
  • 9.6. Single values of participant 43
  • 9.7. Single values of participant 46
  • 9.8. Single values of participant 47
  • 9.9. Single values of participant 48

Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)

This diploma thesis explores the potential alterations of the Sister Chromatid Exchange (SCE) frequency in peripheral lymphocytes caused by an Ironman triathlon. The primary objective is to investigate the effects of intense endurance exercise on the genetic stability of human lymphocytes. The research examines the relationship between exercise-induced oxidative stress and DNA damage.

• Sister Chromatid Exchange (SCE) frequency as a measure of genotoxicity
• The impact of intense endurance exercise on human lymphocytes
• Exercise-induced oxidative stress and its role in DNA damage
• The relationship between oxygen consumption and DNA damage
• Exercise-induced adaptation and its effects on SCE frequency

Zusammenfassung der Kapitel (Chapter Summaries)

The first chapter of this thesis introduces the topic and provides a brief overview of the study. Chapter 2 delves into the background information, covering human lymphocytes, the cell cycle, and the mechanism of SCE. It also explores the scientific significance of the SCE assay, factors influencing SCE frequency, and the correlation between strenuous endurance exercise and genotoxicity. Chapter 3 focuses on the materials and methods employed in the study, including participant selection, blood collection, and the SCE assay procedure. Chapter 4 presents the results and their discussion, analyzing the data collected and drawing conclusions about the effects of Ironman triathlon on SCE frequency. The thesis concludes with a summary of the findings and their implications.

Schlüsselwörter (Keywords)

The primary focus of this research is on Sister Chromatid Exchange (SCE) frequency, human lymphocytes, endurance exercise, oxidative stress, DNA damage, genotoxicity, Ironman triathlon, cell culture, and statistical analysis.

• College: University of Vienna (Institut für Ernährungswissenschaften)
• Grade: 1,0
• Author: Mag.rer.nat. Marlies Meisel (Author)
• Publication Year: 2007
• Pages: 86
• Catalog Number: V86371
• ISBN (eBook): 9783638906739
• ISBN (Book): 9783638910415
• Language: English
• Tags: Alterations, Sister, Chromatid, Exchange, Ironman