In vitro incubation of human spermatozoa promotes reactive oxygen species generation and DNA fragmentation |
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| Authors: | J Cicaré A Caille C Zumoffen S Ghersevich L Bahamondes M J Munuce |
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| Institution: | 1. Laboratory of Reproductive Studies, Clinical Biochemistry Area, School of Biochemical and Pharmaceutical Sciences, National University of Rosario, Rosario, Argentina;2. Human Reproduction Unit, Department of Obstetrics and Gynecology, School of Medical Sciences, University of Campinas (UNICAMP) and National Institute of Hormones and Women's Health, Campinas, SP, Brazil |
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| Abstract: | The aim of this study was to investigate the oxidative process associated with sperm capacitation and its impact on DNA fragmentation and sperm function. Redox activity and lipid peroxidation were analysed in human spermatozoa after 3, 6 and 22 h of incubation in Ham′s F10 medium plus bovine albumin at 37° and 5% CO2 for capacitation. DNA status, tyrosine phosphorylation pattern and induced acrosome reaction were evaluated after capacitating conditions. At 22 h of incubation, there was a significant (P < 0.05) increase in oxygen‐free radicals and lipid peroxidation, with no effect on sperm viability. There also was a significant (P < 0.001) increase in fragmented DNA in capacitated spermatozoa compared to semen values with higher rates being found after the occurrence of the induced acrosome reaction. Protein tyrosine phosphorylation pattern confirms that capacitation took place in parallel with the occurrence of DNA fragmentation. These results indicate that when spermatozoa are incubated for several hours (22 h), a common practice in assisted reproductive techniques, an increase in oxidative sperm metabolism and in the proportion of fragmented DNA should be expected. However, there was no effect on any of the other functional parameters associated with sperm fertilising capacity. |
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| Keywords: | DNA fragmentation dynamics SCD test sperm |
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