Effects of protein kinase C on parthenogenetic activation of pig oocytes using calcium ionophore or nitric oxide-donor

Abstract

Porcine oocytes matured in vitro were activated for parthenogenetic development using either calcium ionophore (50μM for 10 min) or nitric oxide donor SNAP (2mM for 23.5 hours). Protein kinase C (PKC) inhibitors, bisindolylmaleimide I or rottlerin, are able to inhibit parthenogenetic activation induced by calcium ionophore. The rate of activated oocytes decreased from 69% to 2% (P < 0.05) under the effect of bisindolylmaleimide I at a concentration of 0 or 20nM, respectively. The activation rate decreased from 68% to 0% (P < 0.05) under the influence of 0 or 20μM rottlerin, respectively. PKC inhibitors Go6976 or hispidin had no effect on the oocyte activation using calcium ionophore or on oocytes activated by a nitric oxide donor. The activation of oocytes by a nitric oxide donor is not significantly influenced even under the effects of bisindolylmaleimide I or rottlerin. Based on these data we can conclude that the oocyte activation induced by calcium ionophore depends on PKC, especially on PKC-δ. On the other hand, the oocyte activation induced by nitric oxide is independent of the tested isotypes of PKC.

Keywords

• oocyte
• pig
• parthenogenesis
• activation
• calcium ionophore
• nitric oxide