The use of reduced glutathione (GSH) as antioxidant for cryopreserved sperm in dogs

Intermediate-Term Storage of Spotted Halibut (Verasper variegatus) Sperm: Effects of Storage Methods, Extenders Supplemented with Antibiotics and Antioxidants on Sperm Quality

Intermediate-term preservation of sperm assists the reproductive management of fish spermatozoa; however, no information is available on sperm of the spotted halibut, Verasper variegatus. We aimed to identify the optimum diluents, temperatures, dilution ratios, antibiotics, and antioxidants for sperm motility and cell viability. The diluents evaluated were marine fish Ringer’s solution (MFRS), Stein’s solution, 300 mM sucrose, and 300 mM glucose (diluted 1:1 [sperm: diluent], 1:2, 1:4, and 1:10 and stored at 0, 2, 4, and 6 °C). Neomycin and gentamycin (100, 200, 400, and 800 mg/L) and antioxidants (Mito-TEMPO [0, 25, 50, 75, 100, 125, 150, 175, and 200 µM], reduced glutathione [0, 2, 4, 6, 8, and 10 mM], and trehalose [0, 50, 100, 150, 200, and 250 mM]) were assessed in terms of sperm preservation. The most effective condition for cold storage of spotted halibut sperm was Stein’s solution at a dilution ratio of 1:4 at 2 °C, with a combination of neomycin 800 mg/L and 250 mM trehalose that showed spermatozoa motility of > 43% after 60 days. These storage conditions will be valuable for spotted halibut hatcheries.

Effects of Inositol Supplementation in Sperm Extender on the Quality of Cryopreserved Mesopotamian Catfish (Silurus triostegus, H. 1843) Sperm

In this study, the effects of supplemented inositol on sperm extenders were examined on the spermatozoa motility rate and duration, total antioxidant and oxidant status, apoptotic spermatozoa and DNA damage, during the sperm post-thaw process of Mesopotamian Catfish (Silurus triostegus, H. 1843). The semen was frozen in diluents containing different inositol concentrations (5, 10, 20 and 40 mg). Increasing levels of inositol linearly improved the spermatozoa motility rate and duration significantly (p < 0.05). MDA and TOS were linearly decreased, however, TAS and GSH linearly increased (p < 0.05). The increasing inositol levels resulted in a linear and quadratic decrease in DNA damage in the comet assay, 8-hydroxydeoxyguanosine and the determined percentage of apoptotic spermatozoa (p < 0.05). These results suggest that there are many positive effects of the use of supplemental inositol on enhancing sperm cryopreservation efficiency in Silurus triostegus.