Efecto crioprotector de la dimetilformamida, glicerol y su combinación sobre la criosupervivencia de espermatozoides equinos

Abstract

The combination of cryoprotective penetrating agents (CPA), such as glycerol (GLY) and dimethylformamide (DMF), has shown encouraging results in equine sperm cryosurvival. In this sense, this research evaluated the cryoprotective effect of GLY, DMF, and its combination: DMF-GLY, on equine sperm quality and cryosurvival. For this purpose, twenty-four semen ejaculates were collected from four healthy, sexually adult Arabian horses (6 ejaculates/stallion). Each ejaculate was initially diluted with BotusemenSpecial extender and then frozen with Botusemen-Gold extender supplemented with GLY (5%), DMF (5%), and DMF-GLY (3%-3%) using static liquid nitrogen vapors. The fresh and frozen-thawing sperm samples were evaluated for their kinematics variables and membranes integrity using the CASA computerized system (SCA-Evolution-2018) and the double fluorescent test (PI / PNA-FITC), respectively. The results showed that DMF alone or combined with GLY (DMF-GLY) was more effective in protecting equine spermatozoa and producing higher values (P< 0,05) of total (MT, %) and progressive (MP, %) motilities, curvilinear velocity (VCL), the amplitude of lateral head displacement (ALH) and beat-cross frequency (BCF) compared to GLY. The combination of DMF-GLY yielded higher (P < 0.05) strain-line (VSL) and average path velocities (VAP), plasma membrane integrity (IMP, %), and acrosomal membrane integrity (IMA, %) compared to DMF alone or GLY alone. In conclusion, the combination of DMF-GLY supplemented to the 'Botusemen-Gold' non-synthetic-based extender, was more suitable for cryoprotecting Arabian horse sperm based on higher kinematics and membrane integrity compared to glycerol cryoprotectant agent.