The eff ects of extenders containing proline and glutamine on oxidative stress and motion parameters of stallion semen during cold storage

This study examined the eff ects of skimmilk based extenders supplemented withproline and glutamine on motility, lipid peroxidation and enzymatic antioxidant statusof cooledstored equine sperm and determined the role of seminal plasma as well.The semen was collected with artificial vagina. In experiment 1, native semen wasdiluted in skimmilk based extender containing 5mM glutamine and 3mM proline,stored at 5°C and analyzed at 4, 24 and 48 hours storage for motion parameters. Inexperiment 2, semen was centrifugated, sperm pellet resuspended in the extendersand stored at 5°C for 4 hours to determine motion parameters. The level of catalase,glutathione peroxidase activity and malondialdehyde formation was determined forall samples at 4 hours. Glutamine and proline signifi cantly preserved the percentageof motile sperm (76.5 ± 2.7 and 79.4 ± 1 vs 69 ± 1.4), increased the progressive motilityof coldstored semen (66.1 ± 2.5 and 73.7 ± 2.9 vs 56.2 ± 1.4), increased catalaseactivity, and decreased malondialdehyde. However these effects were disappeared afterseminal plasma removal. We conclude that glutamine and proline would amplifythe antioxidant activity of equine coldstored semen and preserve its motility. Thiseffect seems to be related to interactions with seminal plasma.