Lifestyle impact on human sperm oxidative balance

• Autor(a) principal: Cruz, Daniel Filipe Soares Pereira da
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/13262
• topic: Biomedicina; Espermatozóides; Stresse oxidativo; Infertilidade masculina

Infertility is a clinical condition that affects about 15% of reproductive-aged couples worldwide. Half of these cases are due to male factors. A large percentage of male infertility cases are idiopathic, however, in the last years the influence of oxidative stress in decreased semen quality has been discussed. The lifestyle, including consumption of alcohol, tobacco, drugs and the alteration in circadian cycle, has been proposed as responsible for the increase of reactive oxygen species (ROS). This increase leads to an alteration of the balance between oxidants and antioxidant defenses present in the organism, causing oxidative stress. High levels of ROS damage biomolecules – DNA, proteins or lipids – present in sperm cells and may lead to the loss of membrane integrity, DNA fragmentation or even to death by apoptosis. The aims of the thesis was to evaluate the influence of acute lifestyle changes on oxidative balance of sperm cells. Therefore, we analyzed the antioxidant capacity of the sperm, as well as the presence of certain antioxidant proteins, by colorimetric techniques and immunoblotting. We also evaluated the effect of ROS by measuring the protein oxidation. The seminal quality was evaluated by performing a routine semen analysis. The results indicate that there is a relationship between the changes in lifestyle and the amount of antioxidants in sperm, and the most reported change involved the protein superoxide dismutase (SOD). It was also demonstrated that the variation in protein oxidation levels is dependent on the consumption of alcohol and nicotine. In this study it was concluded that oxidative balance of sperm cells is affected by lifestyle changes; in turn, oxidative balance changes is then reflected in semen quality.