氨基酸浓度对昆明小鼠胚胎体外发育的影响

目的探讨培养液中氨基酸成分对植入前昆明小白鼠胚胎发育的影响,摸索植入前胚胎体外培养氨基酸的最佳浓度。方法从超排昆明小鼠输卵管中取出的630枚受精卵均分为7组,分别在经添加不同浓度Eagle's氨基酸的去牛血清白蛋白KSOM培养液(mKSOM、mKSOM 1/16AA、mKSOM 1/8AA、mKSOM 1/4AA、mKSOM 1/2AA、mKSOM AA、mKSOM 2AA)中培养,对比观察各组胚胎体外发育的过程。用卡方检验分析添加各浓度氨基酸的培养液培养效率的差别,并将8细胞发育率和囊胚发育率分别与相应的氨基酸浓度进行曲线拟合分析。结果与未添加氨基酸组对比,添加氨基酸组胚胎发育率高,8细胞胚和囊胚的形成率与培养液中氨基酸的浓度关系均符合三次模型,在氨基酸为1/2浓度时8细胞胚和囊胚的形成率均达到最高。结论氨基酸对胚胎的体外发育有促进作用,但含有高浓度氨基酸的培养液培养效果反而有所下降,可能是由于高浓度的氨基酸影响胚胎的代谢和渗透压的改变,且氨基酸分解及胚胎代谢所产生的铵对胚胎有毒性作用。

Effects of different concentrations of amino acids in the culture medium on preimplantation mouse embryo development in vitro

Objective To evaluate the effects of amino acids (AA) on the development of in vitro cultured preimplantation embryos of Kunming mice, and define the optimal AA concentration for embryo culture. Methods Totally 630 zygotes were collected from the oviducts of superovulated female Kunming mice, which were cultured in protein-free potassium simplex optimized medium (mKSOM) supplemented with Eagle's essential amino acids and Eagle's non-essential amino acids of different concentrations (mKSOM, mKSOM 1/16AA, mKSOM 1/8AA, mKSOM 1/4AA, mKSOM 1/2AA, mKSOM AA, and mKSOM 2AA). Results The embryos cultured with the amino acids showed higher development rate to both 8-cell embryo stage and blastocyst stage than those cultured without amino acids. The correlation of amino acid concentration with 8-cell and blastocyst development rates conformed to the cubic model, with the highest development rate to both of the two stages observed at half of the amino acid concentration. Conclusion Amino acids can promote the development of preimplantation Kunming mouse embryos, but excessively high concentration of amino acids impair embryo development possibly because of metabolic and osmotic pressure changes of the embryos as well as toxicity of ammonium resulting from the metabolism of amino acids.