PGI_2对缺少内源性PGs的绵羊早期胚胎体外发育的影响

Effect of PGI_2 on Potential Development of in vitro Produced Ovine Embryos Which Lacking with Their Endocrinal PGs

试验旨在探讨添加外源Iloprost(PGI2的稳定类似物)对缺少内源性前列腺素(PGs)的绵羊早期胚胎体外发育的影响。常规体外受精,通过在体外培养液中单独或联合添加前列腺素合成限速酶COX-1和COX-2的特异性抑制剂SC560和NS398,观察COX-1和COX-2对绵羊早期受精胚胎体外发育的影响。添加抑制剂NS398后,再协同添加不同浓度Iloprost,观察PGI2对绵羊早期体外胚胎发育的具体作用,并对孵化囊胚的细胞数进行分析。结果显示,在卵裂率和囊胚率方面,单独添加NS398与同时添加SC560和NS398组间差异不显著(P>0.05),而与对照组间差异显著(P<0.05)。添加NS398后,再添加不同浓度的外源性Iloprost可代替胚胎内源性PGI2的作用,基本消除COX-2抑制剂对绵羊早期胚胎体外发育的不利影响。Iloprost的浓度以1×10-6 mol/L为宜,H33342染色结果差异不显著(P>0.05)。本试验结果表明,胚胎内源性COX-2对绵羊早期胚胎中PGI2的合成起主要调控作用。外源添加Iloprost可补偿胚胎内源性PGI2的缺失作用,解除NS398对COX-2的特异性抑制作用,最终促进绵羊早期胚胎的体外发育。

This study was conducted to investigate the effect of PGI2 on early embryo development of sheep in vitro lacking of endogenous prostaglandins（PGs）.The specific inhibitor NS398 and SC560（specifically inhibiting the activity of COX-1and/or COX-2）were added into the culture medium respectively to study the effect of COX-1and COX-2on embryonic development of sheep.Different concentrations of Iioprost were added respectively into the culture medium to investigate the effect of PGI2 on early embryo development of sheep in vitro.The results showed that there were no significant differences on the cleavage and blastocyst rates between the group only with NS398 and that with both NS398 and SC560（P〉0.05）.There were significant differences between the group only with NS398 and control group（P〈0.05）.After adding NS398,different concentrations of exogenous Iloprost could replace the role of embryonic-derived PGI2,which substantially eliminated the adverse effects of COX-2inhibitor on early embryo development in vitro.The appropriate concentration of Iloprost was 1×10-6 mol/L.H33342 staining showed no significant difference（P〉0.05）.The results demonstrated that embryonic endogenous COX-2playedamajor role in regulating synthesis of PGI2 in early embryo of sheep.The exogenous Iloprost was able to compensate for the loss of endogenous PGI2 in embryos and remove the inhibition of NS398 on COX-2,ultimately promoting the development of early sheep embryos in vitro.