Ohsugi M, Yamamura H
Department of Anatomy, Mie University School of Medicine, Japan.
Differentiation. 1993 Jul;53(3):173-9. doi: 10.1111/j.1432-0436.1993.tb00706.x.
Differences are described in the effects of treatment of preimplantation mouse embryos with low levels (0.01-1 nM) of phorbol myristate acetate (PMA), during three different periods of a 48-h culture from the 2-cell stage, on pre- and postimplantation development. Treatment of embryos with PMA for 48 h (first group) or 24 h (second group) from the 2-cell stage caused premature cavitation (prior to the 16-cell stage) and it also reduced the size and alkaline phosphatase (ALPase) activity of inner cell masses (ICMs), as well as the numbers of cells in blastocysts, in a dose-dependent manner. Treatment of early morulae with PMA for 24 h (third group) did not have the above mentioned effects on embryos but inhibited the formation and subsequent enlargement of the blastocoel. The blastocysts that were allowed to develop in the three treatment groups were examined for postimplantation development. Implantation was unaffected in all groups. The survival rate after implantation was low in the first and second groups but relatively high in the third group. The results indicate that an embryo exposed to PMA for 24 h from the 2-cell stage forms a premature blastocoel, and, in such an embryo, quantitative and qualitative differentiation into the ICM is blocked but qualitative differentiation into trophectoderm is uninhibited. Consequently, the embryo can implant but does not survive for a long time. When embryos were exposed to PMA for 24 h from the early morula stage, the formation and enlargement of the blastocoel were inhibited even though the treatment had a minimal effect on other developmental events.(ABSTRACT TRUNCATED AT 250 WORDS)
研究了在从2细胞期开始的48小时培养的三个不同阶段，用低水平（0.01 - 1 nM）的佛波醇肉豆蔻酸酯乙酸酯（PMA）处理植入前小鼠胚胎，对植入前和植入后发育的影响。从2细胞期开始用PMA处理胚胎48小时（第一组）或24小时（第二组），会导致过早空泡化（在16细胞期之前），并且还会以剂量依赖的方式减小内细胞团（ICM）的大小和碱性磷酸酶（ALPase）活性，以及囊胚中的细胞数量。用PMA处理早期桑葚胚24小时（第三组）对胚胎没有上述影响，但会抑制囊胚腔的形成和随后的扩大。对在三个处理组中发育的囊胚进行植入后发育检查。所有组的植入均未受影响。第一组和第二组植入后的存活率较低，但第三组相对较高。结果表明，从2细胞期开始暴露于PMA 24小时的胚胎会形成过早的囊胚腔，并且在这样的胚胎中，向ICM的定量和定性分化被阻断，但向滋养外胚层的定性分化未受抑制。因此，胚胎可以植入但不能长期存活。当胚胎从早期桑葚胚期开始暴露于PMA 24小时时，囊胚腔的形成和扩大会受到抑制，尽管该处理对其他发育事件的影响最小。（摘要截取自250字）
