排卵前期卵泡颗粒细胞端粒酶的表达及其影响因素

用端粒酶重复扩增酶联免疫吸附分析法（telomeric repeat amplification protocol-enzyme linked immunoadsordent assay,TRAP-ELISA）观察体外培养的大鼠排卵前期卵巢颗粒细胞中端粒酶活性的表达及其影响因素,并用放射免疫分析法（radioimmunoassay,RIA）同步测定培养液中雌二醇（estradiol,E2）、孕西阿（progesterone,P0）含量的变化及MTT（四甲基偶氮唑盐）法测定颗粒细胞增殖指数,分析颗粒细胞中端粒酶活性的表达以及端粒酶活性表达的影响因素。本实验中大鼠排卵前期卵巢颗粒细胞中有端粒酶活性表达,且在人绒毛膜促性腺激素（human chorionic gonadotropin,HCG）、卵泡刺激素（follicle-stimu1ating hormone,FSH）、二丁酰环磷腺苷（dbcAMP）及维拉帕米（verapamil）作用下活性明显升高,而在反义c-myb作用下活性明显降低。RIA测定培养液中雌激素及孕激素含量发现,在verapamil及FSH作用下E2与P0分泌量明显升高,在dbcAMP及HCG作用下分泌量无明显改变,而在反义c-myb作用下分泌量明显降低,在不同作用因素下的端粒酶活性与它相对应的E2及P0分泌量无相关性。MTT法测定显示,反义hTERT能明显抑制颗粒细胞的增殖。由此可以证实,排卵前期卵巢的颗粒细胞中表达有端粒酶活性,其活性受FSH、HCG、verapamil、dbcAMP及癌基因的影响,并且端粒酶活性与颗粒细胞增殖功能相关。

Telomerase: the expression and regulatory mechanisms in preovulatory ovarian granulosa cells

The objective of this study was to analyze the expression of telomerase in granulosa cells and the influential factors in telomerase expression. TRAP-ELISA (telomeric repeat amplification protocol-enzyme linked immunoadsordent assay) method was used to study the expression and control of telomerase in rat preovulatory ovary. We also used radioimmunoassay (RIA) to determine the expression of estradiol (E2) and progesterone (P0). Furthermore we used MTT to study the proliferation of ovarian granulosa cells. Telomerase activity was significantly enhanced by human chorionic gonadotropin (HCG), follicle-stimulating hormone (FSH), verapamil and dbcAMP, and was significantly reduced by antisense-c-myb oligodeoxynucleotide (anti-c-myb ODN) treatment. RIA was used to determine the secretion of P0 and E2 in all these cell culture media. We found that the secretion of these two hormones was increased when verapamil and FSH were added; no change after adding HCG and dbcAMP; and reduced when anti-c-myb was added. In MTT assay, we found that the antisense hTERT ODN significantly inhibited the proliferation of ovarian granulosa cells. These results demonstrate that telomerase activity is present in ovary antral granulosa cells and its activity is controlled by FSH, HCG, verapamil and anti-c-myb, and is directly related with the function of proliferation.