MitoTEMPO is an antioxidant that protects the bovine sperm acro-some during cryopreservation

Resumen

Objective: To evaluate the addition of different concentrations of the mitochondrial-targeted antioxidant MitoTEMPO® in a commercial egg yolk-free diluent. Design/Methods/Approach: Reactive oxygen species (ROS) and ATP production were measured post-thawing by fluorescence, while sperm viability, as well as membrane and acrosome integrity, were assessed using eosin-nigrosin and hypoosmotic Coomassie brilliant blue (HOST/Coomassie) staining of cryopreserved bovine spermatozoa in the commercial medium AndroMed®. Three healthy, fertile 3-year-old Brangus bulls were used, with three ejaculates collected from each bull using an artificial vagina. Ejaculates were divided into three groups and frozen: Group 1 (control), Group 2 (25 µM MitoTEMPO®), and Group 3 (50 µM MitoTEMPO®), with the antioxidant added at the time of strawing. One-way ANOVA (Tukey's multiple comparison test) was used to compare the means of motility, live vs. dead sperm, membrane integrity, and acrosome integrity between treatments, with statistical analysis performed using GraphPad Prism Version 5 (GraphPad Software, Inc., La Jolla, CA, USA) at a significance level of p < 0.05. Results: The study demonstrated that the 50 µM concentration improved sperm motility compared to the 25 µM concentration (81.6% vs. 76.6%). Coomassie blue staining revealed that the 25 µM group had a higher percentage of sperm with intact acrosomes compared to both the control and the 50 µM groups (58.88% vs. 36.21% and 36.34%, respectively). No statistically significant differences were observed in eosin-nigrosin staining, the HOST test, ROS production, or ATP levels between the groups.Findings/Conclusions: It is concluded that the 25 µM concentration of MitoTEMPO® helps preserve the acrosomal integrity of spermatozoa after the freeze-thaw process.