Plasmatic and acrossomal membrane integrity and mitochondrial potential evaluation of spermatozoa of the ovine supplemented with selenium

The present study had the objective of evaluating the effects of different concentrations of selenium (Se) supplementation on the integrity of acrosome and spermatic membrane, as well as the mitochondrial potential of ovine spermatozoa. Thirty (30) ovine males, aging from 18 to 24 months old, housed in individual pens, in an intensive system, were divided in 5 experimental groups: GC (n = 5), supplemented with mineral salt without the addition of Se; G1 (n = 5), same mineral salt added with 5mg of Se (sodium selenite)/kg mixed; G2 (n = 5), same mineral salt added with 10mg of Se/kg mixed; G3 (n = 5), same mineral salt added with 15mg of Se/kg mixed; G4 (n = 5), same mineral salt added with 20mg of Se/kg mixed. To each group there was an adaptation time of 14 days, leading to 56 days of treatment. The semen samples were collected using electro-ejaculation. The analyzes were performed with a flux cytometry, BD LSR II (Becton Dickinson, Mountain View, CA, USA) equipped with lasers: blue 488 nm, 100 mW and red 640 nm, 40 mW. The data were evaluated by a program of the same enterprise BD FACSDiva™ software v6.1. In order to evaluate the integrity of acrosome and plasmatic membrane, the propidium iodete (IP; P4170, Sigma), FITC-PSA (L0770, Sigma) and Hoescht 3342 (H342; 14533, Sigma) probes were associated. A 20 0 µL semen was diluted in TALP at the concentration of 10 x 106 spermatozoa/mL, added with 5 µL of H342 (7 µM), 5µL of IP (1,5 µM) and 0,5 µL of FITC-PSA (2ng), homogenized and incubated for 15 minutes at 37oC protected from light. The experimental design was developed by a Latin square 5 x 5, or five treatments and five experimental periods. The data were analyzed using the GLM procedure of SAS (2009). The mean differences among the groups were verified by Tukey`s test at 5% of significance. The integrity of acrosome and plasmatic membrane, as well as the mitochondrial potential did not show any statistical differences among the treatments, showing no influence of treatment at the parameters evaluated, despite Meseguer et al. (Drug Metab Lett, v.1, p.121- 126, 2007), who described an anti-oxidation effect of Se especially at the middle piece`s mitochondrial activity. Due the presented results, the selenium supplementation (with the studied concentrations) did not bring any benefit at the membrane integrity (acrosome and/or plasmatic) and at mitochondrial potential of ovine spermatozoa.