Produção Nacional
Revisado por pares
Effects of reduced glutathione on the free cysteine radicals and reactive oxygen species levels in boar sperm during the in vitro capacitation
2017; Colégio Brasileiro de Patologia Animal (CBPA); Volume: 14; Issue: 1 Linguagem: Inglês
ISSN
1984-3143
AutoresR. P. Betarelli, W. E. Silva, Monica Rocco, Joan E. Rodríguez‐Gil, Carla Oliveira Resende, Stênia Severo Rabelo, Márcio Gilberto Zangerônimo,
Tópico(s)Reproductive Biology and Fertility
ResumoNowadays, with the advent of assisted reproductive technologies through of in vitro studies a large amount of information has been gathered on how the sperm achieves the capacitation through a sequence of biochemical modifications that lead to the establishment of fully fertilizing ability. However, little is known about the possible effects of antioxidants such as reduced glutathione (GSH) on these cellular changes during sperm capacitation.Thus, the aim of this study was to evaluate the effects of GSH on the putative changes in free cysteine radicals (FCR) and reactive oxygen species (ROS) levels in the boar sperm of cooled semen during the achievement of a standard in vitro capacitation (IVC). Four treatments (control and three different GSH concentrations: 1, 2 and 5 mM) for each assay (n=6) were analyzed after the incubation for 4h at 38.5oC (in a 5% CO2 atmosphere) of sperm in an IVC activation medium (CM) containing NAHCO3 and bovine serum albumin (BSA). The incubation increased (P<0.05) the intracellular levels of FCR in both head (from 3.0 ± 0.3 nmol/µg protein at 0h to 17.4 ± 1.7 after 4h of incubation) and tail (from 3.4 ± 0.4 nmol/µg protein at 0h to 8.4 ± 1.0 nmol/µg protein after 4h of incubation). Similarly, an increase (P<0.05) in the rate of sperm with high intracellular levels of both peroxides (from 2.4 ± 0.7% at 0h to 18.6 ± 2.0% after 4h of incubation) and superoxides (from 11.6 ± 1.7% at 0h to 17.5 ± 1.9% after 4h of incubation) was observed. These increases were concomitant with capacitation-like changes of parameters like sperm motility, membrane fluidity, mitochondrial membrane potential and tyrosine phosphorylation levels. The addition of GSH at the CM prevented the majority of these changes in a dose dependent manner, reaching a maximal effect at concentrations of 5 mM. Our results seem to indicate that IVC in boar sperm is related with an increase of both overall disrupted disulfide bonds and intracellular ROS levels which can be prevented by the addition of GSH to the medium.
Referência(s)