Effect of long-term cryopreservation on physiological characteristics, antioxidant activities and lipid peroxidation of red seabream (Pagrus major) sperm.

The aim of this study was to determine the effect of long-term cryopreservation on physiological characteristics, the antioxidant activities and lipid peroxidation of red seabream sperm which were respectively cryopreserved with 15% dimethylsulfoxide (Me(2)SO) for 1 month, 13 months, 26 months, 48 months and 73 months. The motility and fertility of post-thaw sperm decreased with the storage time going on. The highest motility (87.67±2.52%) was obtained in sperm cryopreserved for 1 month and the lowest (50.67±5.31%) was in sperm for 73 months. There were no significant differences (p<0.05) in fertilization rates of sperm cryopreserved for 1 month (71.33±8.84%), 13 months (69.22±1.02%) and 26 months (60.33±2.33%); however, the sperm fertility decreased significantly for 48 months (47.22±3.89%) and 73 months (39.56±0.69%) storage. In addition, superoxide dismutase (SOD) activities of sperm were at a stable level for less than 26 months storage, then, decreased significantly after 48 months storage. Catalase (CAT) activities of sperm cryopreserved for 13 months, 26 months, 48 months and 73 months were significantly lower than that for 1 month. There were no significant differences in the malondialdehyde (MDA) level of sperm for less than 13 months storage. After 26 months storage, the concentration of MDA increased significantly, and the highest concentration (3.22±0.05 nmol/mgprot) was obtained in 73 months storage sperm.