Incubação com pentoxifilina do espermatozoide bovino capacitado

Abstract

The aim of the present study was to evaluate the effect of different concentrations of pentoxifylline on the viability, quality and oxidative stress in post-thawed and in vitro capacitated bovine sperm. Cryopreserved samples of nine Nellore bulls (Bos taurus indicus) were submitted to selection and sperm capacitation using a 45% and 90% Percoll® gradient. Samples were ressuspended in fertilization medium, and assigned in three treatments: control (miliQ water), 2.5 mM pentoxifylline and 5.0 mM pentoxifylline. Then, the samples were incubated in a water bath at 37 ° C for 3 minutes. After incubation, sperm motility and vigor, plasma membrane viability, mitochondrial cytochemical activity, acrosomal membrane integrity and oxidative stress were assessed. The data were analyzed by ANOVA, Wilcoxon and Tukey test. Significance level was set as 5% using SAS System version 9.2 software. Oxidative stress was higher in 2.5 mM treatment compared to the control and 5.0 mM pentoxifylline treatments (0.42 ± 0.06 0.28 ± 0.04 and 0.31 ± 0.04 ng / mL TBARS, respectively). A higher percentage of sperm with no mitochondrial cytochemical activity (DABIV) in 5.0 mM treatment (10.32 ± 1.39%) was was noticed in comparison to 2.5 mM treatment (5.89 ± 1.95%) and control (5.67 ± 1.17%). No differences were observed among treatments for the remaining variables. Therefore, the addition of pentoxifylline at 2.5mM and 5mM was not efficient to improve the sperm parameters of thawed bovine sperm, capacitated and submitted to in vitro incubation.