Pig oocytes matured in vitro were parthenogenetically activated using nitric oxide donor (SNAP). Continuous treatment successfully activated the oocytes only after more than 12 hours of exposure. Pulsatile treatments were more efficient with regard to the activation rate. The development was very limited after continuous treatment with SNAP. A significantly higher proportion of developing embryos was observed after the pulsatile treatment. However, this developmental rate was significantly lower than the development induced by treatment with calcium ionophore. After combination pulsatile treatment with the effect of protein kinase inhibitor 6-dimethyl aminopurine (6 DMAP) or with the inhibitor of protein synthesis cycloheximide (CHX) a significant increase in the activation rate when compared to the respective pulsatile treatment was observed. However, the development of parthenogenetic embryos was not enhanced when the pulsatile treatment was combined with 6-DMAP or with CHX..