Effect of cryopreservation on the enzyme activity of Russian sturgeon (Acipenser gueldenstaedtii Brandt & Ratzeburg, 1833) semen

Summary The hypothesis was tested that cryodamage occurs during the storage of semen at −196°C and that cryopreservation has a negative effect on the enzyme activity and motility of semen in the Russian sturgeon, Acipenser gueldenstaedtii. In addition, the aim of the study was to determine the activity of metabolic enzymes, including adenosintriphosphatase (total ATPase), creatine kinase (CK), succinate dehydrogenase (SDH) and lactate dehydrogenase (LDH), plus antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GR). After cryopreservation (storage at −196°C), the motility and duration of semen fell and the total ATPase, SDH, LDH and CK activity in the spermatozoa was reduced. In the seminal plasma, however, total ATPase, SDH, LDH and CK activity increased markedly. Activity also notably increased in the group with no diluents or cryoprotectants. SOD, CAT and GSH-Px activities also increased in the seminal plasma but dropped with regard to the spermatozoa, whereas the GR activity varied. The antioxidant enzyme activity trend between the groups with and without the addition of cryoprotectants was the same as in the metabolic enzyme activity. Cryopreservation had a great effect on the enzyme activity and motility of A. gueldenstaedtii semen; however, the cryoprotectant protected the semen during cryopreservation.