Adição dos antioxidantes Trolox e glutationa reduzida ao diluidor de criopreservação de sêmen de cães

Abstract

In order to evaluate the effect of adding antioxidants Trolox and Glutathione reduced on the in vitro viability of dog cryopreserved sperm, semen samples were harvested from animals of the breeds French Bulldog (n=1), Basset Hound (n=2) e Rottweiler (n=1), through digital manipulation. Then proceeded to the evaluation macroscopic (color, appearance, volume) and microscopic (progressive motility, vigor, DNA, acrosome integrity and oxidative stress), followed by dividing the volume of semen on four aliquots, according to the experiments and experimental groups: Experimental 1 - G1 = Tris- Egg yolk (control group); G2 = Tris- Egg yolk + 200 uM of Trolox and G3 = Tris- Egg yolk + 300 uM of Trolox; Experimental 2 - G1 = Tris- Egg yolk (Control group); G2 = Tris- Egg yolk + 2 uM of GSH and G3 = Tris-Egg yolk + 5 uM of GSH; Experimental 3 - G1 = Tris- Egg yolk (control group); G2 = Tris- Egg yolk + 200 uM of Trolox; G3 = Tris- Egg yolk + 2 uM of GSH and G4 = Tris- Egg yolk + 200 uM of Trolox + 2 uM of GSH. The samples were packaged in straws (0.25 mL), cryopreserved in freezing machine (TK3000) and stored in liquid nitrogen (-196 oC). After thawing a 37 oC and incubation during 60 minutes, it was detected that MP, vigor and sperm with intact acrosomes had significant difference (P<0.05) only among incubation times, on the three experiments. In the Exp. 2, G2 and G3 groups had higher (P<0,05) percentage of sperm with oxidative stress. So, it can be concluded that the incubation time interfere on the in vitro viability of the sperm cells, independently of Trolox and GSH addition; and GSH, on the concentration of 2 and 5 uM, should be added to diluent of dog semen cryopreservation.