320 SUSCEPTIBILITY OF GOAT SPERM TO DIFFERENT REACTIVE OXYGEN SPECIESR. O. C. Silva A , E. G. A. Perez A , R. P. Cabral B , D. G. Silva B , C. H. C. Viana B , M. Nichi A , P. A. A. Goes A , G. H. Ferreira B , A. C. Teodoro B , R. C. Barnabe A and V. H. Barnabe A
A University of São Paulo, São Paulo, Brazil;
B Pontifícia Universidade Católica, Poços de Caldas, MG, Brazil
Reproduction, Fertility and Development 22(1) 316-316 http://dx.doi.org/10.1071/RDv22n1Ab320
Published: 8 December 2009
Semen quality is one of the main limiting factors for the success of artificial insemination in goats. It is well known that reactive oxygen species (ROS) lead to structural and functional damages to sperm, impairing or avoiding fecundation. The understanding of sperm oxidative mechanisms in goats may provide information on possible treatments to improve semen quality and fertility rates. The aim of the present study was to verify the resistance of goat spermatozoa to different reactive oxygen species. Sperm samples from 4 goats were collected using an artificial vagina. Sperm samples were then incubated (1 h, 37°C) with 4 ROS inducer mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate/ferrous sulfate (4 mM; produces hydroxyl radical), and malondialdehyde (MDA, lipid peroxidation product). Samples were analyzed for mitochondrial activity using the 3,3′ diaminobenzidine stain, for membrane integrity using the eosin/nigrosin staining, for acrosome integrity using the simple stain (fast green/Bengal rose), and for lipid peroxidation by dosing thiobarbituric acid reactive substances (TBARS). Results showed that goat sperm is more sensitive to hydrogen peroxide, when compared to superoxide anion, hydroxyl radical, and MDA, when considering acrosome integrity, membrane integrity, and mitochondrial potential (Table 1). On the other hand, TBARS production was increased in samples submitted to hydroxyl radical incubation. Strong negative correlations were found between sperm samples showing impaired mitochondrial potential and both membrane and acrosome integrity (r = -0.97, P < 0.0001 and r = -0.91, P < 0.0001, respectively). The concentration of TBARS correlated negatively with the percentage of sperm showing intact membranes (r = -0.53, P = 0.06), and the later correlated negatively with sperm showing no mitochondrial activity (r = -0.78, P = 0.0006). Results of the present experiment suggest that goat sperm are extremely susceptible to the attack of hydrogen peroxide, being resistant to other ROS. Therefore, an alternative to improve the use of goat semen in reproductive biotechnologies would be the treatment with catalase or glutathione peroxidase, important hydrogen peroxide scavengers.
The authors thank Nutricell for the media used in this experiment.