Dimethylsulfoxide, methanol and methylglycol in the seminal cryopreservation of Suruvi, Steindachneridion scriptum

The aim of this study was to analyze the effect of 5%, 7.5%, 10%, 12.5% and 15% dimethylsulfoxide (DMSO), methanol and methylglycol alcohols on the cryopreservation of sperm from Steindachneridion scriptum. Male specimens (n = 15) were obtained from Pisciculture and sperm samples were collected by abdominal massage. Post collection the fresh sperm sample was diluted in the Beltsville Thawing Solution and sperm motility was evaluated. Results indicated that the most precise parameters for total and progressive motility were obtained with the use of methylglycol (all concentrations) and 7.5% and 10% methanol (P < 0.05). The motility of the sperm was sustained for the longest time period when 5%, 7.5% and 15% DMSO was used; similar results were also seen for 5% methanol and methylglycol at 7.5%, 10%, 12.5%, and 15% concentration (P < 0.05). With respect to reactive oxygen species it was observed that the production of ROS decreased only in presence of 5% methylglycol but not when DMSO (5%) was used (P < 0.05). Although the use of methanol (12.5%) allowed for a lesser membrane fluidity as compared to DMSO 12.5% (P < 0.05), membrane functional integrity was greater with 10% and 12.5% DMSO (P < 0.05) as compared to 10% methanol or 5% methylglycol (P > 0.05). Additionally, when major mitochondrial functionalities were assessed it was observed that the values obtained with use of 12.5% and 15% DMSO were comparable to all except 5% methyglycol (P < 0.05). In conclusion, the results of the present study indicate that 7.5% methylglycol was the most effective treatment for the cryopreservation of the S. scriptum sperm.