Effect of albumin and zinc on capacitation and acrosome reaction of buffalo spermatozoa

Abstract

Sperm capacitation and acrosome reaction are important events before fertilization. In this study, the role of zinc on these 2 processes has been studied in buffalo. After discarding seminal plasma, sperms were washed with albumin saline (AS), swimmed up and incubated in 'AS', TALP (containing BSA, L-glutamine and sodium pyruvate as energy sources and taurine and epinephrine as motility factors) and TALP + Zn acetate (TZ). Samples were taken at 0 h and after hourly duration to check its viability, motility, capacitation, acrosome reaction and for quantitative estimation of proteins (P), acid phosphatase (ACP) and alkaline phosphatase (AKP). Capacitation started after 1 h and was maximum at 3 h in TALP. In 'TZ' medium, the motility decreased significantly at 1 h followed by 100% immotile sperms at 3 h. Acrosome reaction started at 2 h in TALP and its percentage increased with time and maximum at 5 h of incubation in TALP. Concentration of proteins and specific activity of ACP did not differ significantly among treatments at specific time of incubation. In TALP, ACP activity was maximum at 3 h of incubation and minimum at 5 hour of incubation while AKP activity decreased after 2 h of incubation in TALP and AS media. It is concluded that among the 3 media used in this study, TALP containing Zn2+removing agent (albumin) and various other energy sources is most suitable incubation medium for buffalo sperm capacitation and acrosome reaction. Addition of Zn2+ to TALP drastically inhibit capacitation and acrosome reaction. This study will improve the understanding of the physiological significance of albumin and zinc in Murrah buffalo spermatozoa during capacitation and acrosome reaction. In addition, this is the first study on the changes in the concentration of total proteins and activities of phosphatases under such conditions.