Influence of different forms of culture on the nitric oxide action on maturation and membrane integrity on bovine cumulus-oocyte complex

Abstract

The aim of the present study was to evaluate the influence of different forms of in vitro culture on the nitric oxide action in maturation and membrane integrity on bovine cumulus-oocyte complex. No significant effect was observed between different forms of culture (mineral oil vs plate; P > 0.05), as much for membrane integrity as for expansion of the CC. However, it was observed that oocytes of the groups control and 10-3 M of SNP, cultivated in plate, had presented greater percentage of cell with maintenance of membrane integrity than same treatments cultivated in drop. The addition of 10-3 M of SNP showed an inhibitory effect on the expansion and membrane integrity of CC and oocytes in both, culture in drops under oil and plate (P < 0.05). The culture form did not intervene with the extrusion of the first polar corpuscle and the addition of 10-3 M of SNP inhibited this extrusion in the both systems (P < 0.05). There was a dose-response effect on the concentration of NO in the maturation medium in both types of cultivation (P < 0,05), and this was higher in the culture medium under oil, except when added 10-3 M of SNP, treatment in which there was no difference in the types of cultivation employed. (P<0.05). These data demonstrate that the culture system did not intervene with the action of the NO in the maturation in vitro of bovine COC, but intervened with the integrity of the plasmatic membrane of the oocyte.