促性腺激素促进雄性小鼠体内卵巢移植体卵泡卵母细胞生长发育的研究

Development of Oocytes and Follicles in Grafted Ovaries in Male Recipient Mice Stimulation by Gonadotrophins

【目的】探索外源促性腺激素对卵巢在雄性受体内生长、卵泡发育和卵母细胞成熟与发育能力的影响。【方法】将1日龄小鼠卵巢移植到7～12周龄雄性小鼠肾囊下,回收前用促性腺激素对受体进行处理或不处理,同龄雌性小鼠用促性腺激素进行处理后作为对照。移植21d后回收移植卵巢,观测移植体的回收率及生长和卵泡发育;对卵母细胞进行体外成熟、体外受精,观察2-细胞胚和囊胚发育率。【结果】移植21d后,未处理组移植体回收率为85.4%,与处理组(90.7%)差异不显著(P>0.05)。未处理组移植体卵泡发育至成熟阶段,回收卵母细胞均处在GV期,平均每枚移植体回收卵母细胞数为(41.4±25.8)枚,2-细胞胚胎发育率为17.5%,未能发育至囊胚;处理组移植体有黄体形成,有的卵泡中有扩展的卵丘卵母细胞复合体,平均回收卵母细胞数为(33.4±20.1)枚,其中MⅡ期卵母细胞为(8.5±7.1)枚,GV期、MⅡ期卵母细胞受精后2-细胞胚胎的发育率分别为33.9%和44.3%,囊胚发育率分别为0.48%和6.3%;试验组间回收卵母细胞数差异不显著(P>0.05),2-细胞胚胎发育率、囊胚发育率差异极显著(P<0.01)。试验组卵母细胞2-细胞胚胎发育率显著低于对照组(P<0.01),处理组MⅡ期卵母细胞囊胚发育率与对照组差异不显著(P>0.05)。【结论】外源促性腺激素对雄性小鼠卵巢移植体具有促进卵泡发育、卵母细胞成熟和胚胎发育的作用,但不增加卵母细胞产量。

[ Objective] This experiment was made to investigate the effect of gonadotrophin on follicle development and oocyte maturation and development in grafted ovaries in male recipient mice. [Method] Ovaries from 1-day-old mice were xenografted underneath the kidney capsule of 7-12-week old male recipient mice. Graft recipients were treated with or without xogenous gonadotrophin prior to graft collection. The 7-12-week old female mice were treated with gonadotrophin and used as controls. Twenty-one days after grafted, the ovarian grafts were recovered for examination of their size, recoverable proportion and follicular growth. The oocyte maturation and fertilization were conducted in in vitro. The 2-cell cleavage rate and Blastocyst rate were determined. [Result] The ovary recovery rate was 85.4% in recipients without treatment, insignificantly differed from the treated group （90.7%） （P〉0.05）. The follicles of grafts could develop to maturation stage and GV oocytes of（41.4±25.8） per ovarian graft were retrieved. The in vitro matured GV oocytes could develop to two-cell embryos in the rate of 17.5%, but not to blastocyst in the non-treated group. The follicles could develop to the antral stage and undergo periovulatory changes following xenografting and exposure to a luteinizing stimulus, with expanded cumulus-oocyte complex, mucified cumulus cell and corpus luteum. MII oocytes as well as GV oocytes were retrieved from the treated group, the yield of MII and GV oocytes per ovarian graft was （8.5±7.1） and （33.4±20.1）, the two-cell cleavage rate was 44.3% and 33.9%, and the blastocyst rate was 6.3% and 0.48%, respectively. There was a significant difference in the two-cell cleavage rate and blastocyst rate between groups treated with or without xogenous gonadotrophin （P〈0.01）, but not in the yield of oocytes （P〉 0.05）. The two-cell cleavage rate of oocytes collected from 21 d grafts was lower than that of the control group （P〈0.01）, and without significant difference in the blastocyst rate between MII oocytes from the grafts and the control （P〉0.05）. [Conclusion] Stimulation with exogenous gonadotrophins did not significantly increase oocyte yield of grafted ovaries in male recipients but did enhance the competence of follicular growth, oocyte maturation and embryo development.