MAPK和p90rsk在大鼠卵泡发育中的表达与活性

利用免疫组织化学方法研究丝裂原激活蛋白激酶(mitogen-activated protein kinases, MAPK)及其底物之一p90rsk在大鼠卵泡发育过程中的表达与活性.结果表明,非活性形式的MAPK存在于大鼠各生长期卵泡的卵母细胞和颗粒细胞中,但磷酸化活性形式的MAPK只存在于部分具有分裂增殖活性的颗粒细胞中.MAPK的作用底物p90rsk只在各期卵泡的卵母细胞中表达,在颗粒细胞中无着色,说明MAPK信号级联在卵母细胞和颗粒细胞中具有不同的作用方式.另外,胎鼠卵巢的免疫组化染色结果显示,MAPK在卵原细胞增殖过程中具有活性,表明MAPK信号级联在这一过程中起作用.

The Expression and Activation of MAPK and p90rsk during Folliculogenesis in Rat

The expression and phosphorylation of mitogen-activated protein kinases (MAPK) and the expression of p90 rsk , one of the substrate of MAPK, in immature and mature rat follicle growth have been investigated by immunohistochemical staining with antibodies against ERK2, active MAPK and p90 rsk. The results show that ERK2 was expressed in both granulosa cells and oocytes at all stages of developmental follicles, whereas phosphorylated MAPK was detected only in some granulosa cells, which were in proliferation. Meanwhile, p90 rsk was exclusively expressed in oocytes, and could not be detected in granulosa cells, it maybe represented that the differences of the action pattern of MAPK cascade in oocyte and granulosa cell. The phosphorylation of MAPK was also detected in oogonia from fetal rat ovaries, suggesting that MAPK play a role in the mitosis of oogonia.