γ-氨基丁酸(GABA)通过调节细胞增殖参与小鼠胎盘的形成

γ-amino butyric acid(GABA) is Involved in the Mouse Placentation by Regulating the Cell Proliferation

目的：探讨r-氨基丁酸（GABA）信号对小鼠胎盘形成的影响。方法：免疫组织化学检测妊娠小鼠第9日至第14日（D9-14）胎盘中GABA的表达，对D7-13孕鼠腹腔注射0．04gg/kg、0．20g/kg、1．00g/kg（gGABA，D14时称量各组胎盘和胚胎，HE染色观察胎盘形态学变化，免疫组织化学检测增殖细胞核抗原（PCNA）表达情况。结果：GABA主要表达于D9的外胎盘锥（ecto—placentalcone，Epc）、D10的绒毛膜板（chorionicplates，Cp）和D11～14的海绵滋养细胞层（spongiotrophobIast，Sp）。与对照组（生理盐水）比较，不同浓度的GABA处理组的胚胎质量均显著下降（P〈0．001），胎盘蜕膜区明显增厚，而海绵滋养层变得较密集并失去海绵样结构，随着GABA浓度增加，迷路滋养层变薄，胎儿血窦及母体血管减少。同时，O．20eJkg和1．00g/kgGABA处理组的蜕膜区、海绵滋养层和迷路滋养层中处于增殖期的细胞数量明显增多，差异有极显著统计学意义（P〈0．001）。结论：GABA可能通过调节蜕膜细胞和滋养层细胞的增殖，从而参与了小鼠胎盘的形成过程。

Objective： To study the potential role of γ-amino butyric acid （GABA） in mouse placentation. Methods： Immunohistochemistry was applied to detect the expression of GABA in mouse placentas on D 9-14 of pregnancy. Pregnant mice were received daily intraperitoneal injections of GABA at concentra- tions of 0.04 g/kg, 0.20 g/kg and 1.00 g/kg, respectively from D 7 to D 13. The weight of embryos and placentas was measured and the structure of placenta was examined by HE staining on D 14. Besides, the proliferation of placenta was evaluated by expression level of proliferating cell nuclear antigen （PCNA） using immunohistochemistry. Results： GABA was mainly located in ecto-placetal zone （Epc） of placenta on D 9, Cp on D 10 and spongiotrophoblast （Sp） from D 9 to D 14. The weight of embryos significantly decreased in different concentration groups of GABA compared with control groups （P〈0.001）. Surprisingly, the proliferation of decidual cells and trophoblast cells in Sp zone and labyrinth zone was abnormally obvious in concentrations of GABA with 0.20 g/kg and 1.00 g/kg group compared with control groups （P〈0.001）. At the same time, the fetal and maternal blood sinusoids were reduced in labyrinth, and the structure of Sp was abnormal by HE staining. Conclusion： GABA may play an important role in mouse placentation via regulating the proliferation of decidua basalis and spongiotrophoblast cells.