Cell Viability, Acrosomal Status and DNA Integrity in Porcine Sperm Permeabilized with Streptolysin O

The aim of this study is to determine the use of streptolysin O (SLO), to open pores on the plasmatic membrane of the swine sperm, to see the effect on the viability, functional status and integrity of nuclear chromatin. 30 ejaculates were used; immediately after collection, semen was diluted in a solution of BTS (2:1, v/v preheated to 35ºC). Two aliquots of semen samples were assigned to each group, of which: Group 1. 0.3 IU/ml SLO, Group 2. 0.6 IU/ml, Group 3 1.2 IU/ml, and Group 4 Control (PBS). All groups were incubated for 5 minutes at 37ºC, in SLO; after this period, the samples were incubated in 5% fetal bovine serum (FBS) for 15 minutes at 37ºC. Each treatment were evaluated before and after incubation with FBS (to close the pores), in duplicate. Sperm viability, acrosome status and integrity of the nuclear chromatin were evaluated with eosin nigrosine (NE), chlortetracycline (CTC) and acridine orange (AO) stains, respectively. The data obtained was analyzed by comparing proportions in each treatment using non-parametric module of STATISTICA V10.0 program. The Kruskal Wallis H test was used for the analysis. In assessing sperm viability each of the treatments were compared in between, and the resulting differences were also compared with the control group (iv). There was no difference in the proportion of viable sperm, using the concentration of 0.6 IU/ml, before and after sealing of pores (83.15±9.10 vs 91.52±4.83) (p>0.05). And mathematical trend indicates that, after sealing the pores, a higher sperm proportion were viable in both treatments. However, no statistical differences were found (P>0.05). Also no changes were found in patterns of acrosomal status and DNA integrity, suggesting that the SLO executes its permeabilizing effect at the level of sperm membrane.