Effects Of Schisandrin B On Quality And Capacitation Status Of Boar Sperm Preserved At Low Temperature

There are three main ways to preserve boar semen:normal temperature preservation（15-17℃）,low temperature preservation（4℃）,ultra-low temperature preservation（-196℃）.Due to the fast metabolism,endogenous bacteria are easy to breed during normal temperature preservation,which is not conducive to the long-term preservation of sperm.Because the plasma membrane of boar sperm is rich in unsaturated fatty acids and special membrane structure,it is extremely sensitive to cold stimulation.At present,ultra-low temperature preservation can not be used for large-scale production.Under the condition of low temperature,sperm is in semi dormant state,ROS and harmful metabolites are reduced,and the breeding of endogenous bacteria is inhibited.These conditions make the study of low temperature preservation be of high practical significance.Therefore,the experiment was designed to explore the effect of schisandrin B on the quality of boar sperm after low temperature preservation by adding schisandrin B to the preservation base solution,so as to provide reference data for improving the low temperature preservation of boar sperm.The specific research contents and results are as follows:（1）The effect of schisandrin B on the routine parameters of boar sperm after low temperature preservation.The addition of schisandrin B to the low-temperature basal solution improved the mobility,plasma membrane integrity,acrosome integrity,wobbility,average movement velocity and mitochondrial membrane potential of sperm after low-temperature preservation（P<0.05）,and reduce the deformity rate and DNA damage（P<0.05）.Conclusion:schisandrin B can improve the quality of boar sperm after olow temperature preservation.（2）Effects of schisandrin B on antioxidant capacity of boar sperm after low temperature preservation.The effects of schisandrin B on T-AOC,ROS and MDA of boar sperm after low temperature preservation were detected by detection kit.RT-PCR was used to detect the m RNA expression levels of SOD,CAT and GPx in boar sperm after low temperature preservation.Schisandrin B reduced the contents of ROS and MDA（P<0.05）,increased the expression levels of T-AOC,SOD and CAT gene m RNA（P<0.05）.Conclusion:adding schisandrin B to the basic solution of low-temperature preservation can improve the antioxidant capacity of boar sperm after low-temperature preservation.（3）The effect of schisandrin B on the capacitation state of boar sperm after low-temperature preservation.The Ca²⁺concentration,lactic acid content,PKA activity and the expression levels of PSP-I and PSP-II genes in the experimental group decreased（P<0.05）,while the expression level of AWN gene increased（P<0.05）.Conclusion:schisandrin B can inhibit the capacitation level of boar sperm after low temperature preservation.（4）Analysis on the possibility of de capacitation of boar sperm after capacitation treatment caused by schisandrin B.There was no significant difference in Ca²⁺concentration,lactic acid content,adhesion protein gene expression level and PKA and PKG activities between the experimental group and the control group（P>0.05）.Conclusion:schisandrin B added after sperm capacitation can not reverse the capacitation state of sperm.In conclusion,adding schisandrin B to the basic dilution of boar sperm at low temperature preservation can improve the quality of boar sperm after cryopreservation.The possible reason is that schisandrin B improves the antioxidant capacity of boar sperm and the passive capacitation of sperm caused by low temperature environment.But schisandrin B could not reverse the capacitation state of capacitated sperm.