Assessment of ovarian fecundity in terms of telomere length and telomerase activity.

为了将端粒酶活性应用于癌症的临床诊断和治疗，人们对端粒酶活性进行了大量研究。关于具有高度增殖活性的生殖细胞的研究很少。本研究旨在探讨端粒酶活性与卵子和胚胎发育的关系。在体外受精-胚胎移植(IVF-ET)中，每个卵泡分别被注射器抽吸，并从每个卵泡液中获得壁状颗粒细胞和卵丘颗粒细胞。用TRAP法检测两种颗粒细胞的端粒酶活性。用小鼠卵母细胞检测卵母细胞端粒酶活性，TRAP法检测卵母细胞和胚胎发育过程中端粒酶活性的变化。卵丘和壁层颗粒细胞均检测到端粒酶活性。壁层颗粒细胞活性高于卵丘颗粒细胞。端粒酶活性在不同发育阶段的卵母细胞和胚胎中均有表达。在卵母细胞阶段，注射PMS后24小时的卵母细胞显著高于注射PMS后48小时、hCG后4小时、8小时和排卵后的卵母细胞。在胚胎期，端粒酶活性在1、2和胚胎期较低，在囊胚期端粒酶活性开始升高，因此端粒酶活性在卵母细胞和胚胎的发育过程中处于波动状态，可能对卵母细胞和胚胎的发育有影响。

Many studies of telomerase activity has been performed for the clinical application to diagnosis and treatment of cancer. Few studies have been performed about the reproductive cells which have highly proliferative activity. In this study, the relationship between telomerase activity and the development of eggs and embryos was examined.In IVF-ET of human, each follicle was aspirated separately by each syringe and mural granulosa cells and cumulus granulosa cells were obtained from each follicular fluid. Then telomerase activity of both kinds of granulosa cells were measured by TRAP assay. And the telomerase activity of oocyte was measured using mouse oocytes and the fluctuation of the telomerase activity during the developmental stage of oocyte and embryo was examined by TRAP assay.Telomerase activity was detected in both cumulus and mural granulosa cells. And the activity of mural granulosa cells was higher than that of cumulus granulosa cells. Telomerase activity was also present in both oocytes and embryos at various stages. In the oocyte stages, the oocyte 24hrs after PMS injection showed the higher than that of the oocytes 48 hrs after PMS, 4 and 8 hrs after hCG and just after ovulation. In the embryo stages, the telomerase activity was low at one, two and molura stage and the activity started to increase at blastocyst stage.Thus the activity of telomerase is fluctuating during the development of oocyte and embryo, and might have effects of the development of oocyte and embryo.