酪氨酸、米非司酮和睾酮对大鼠颗粒细胞凋亡的影响

大多数哺乳类动物的卵巢卵泡在排卵前闭锁，研究表明其发生机制是细胞凋亡。本实验观察了卵巢调控因子酪氨酸、米非司酮和睾酮对大鼠卵巢颗粒细胞凋亡的影响。结果：米非司酮和睾酮促进凋亡，造成ＤＮＡ的片段化反应；而酪氨酸的作用则相反。与对照组相比，米非司酮和睾酮组血清雌二醇含量下降而孕酮含量升高；酪氨酸组血清雌二醇水平升高而孕酮水平下降。米非司酮和睾酮增加闭锁卵泡数，酪氨酸作用则相反。

Effects of tyrosine , mifepristone and testosterone on the apoptosis of granulosa cell in rat

National Research Institute for Family Planning Objectives :To investigate the effect of tyrosine ,mifepristone and testosterone on rat granulosa cell apoptosls Design:Experimental study on rat granulosa cell.Settings :Harbin Medical University,Molecular Biology Laboratory in National Research Institute Planning.Methods :Immature female rats were injected 1 5 IU PMSG for 2 days,followed by daily injection of ty- rosine( 2mg/rat )or mifepristone(1mg/rat )or twice a day of testosterone( 0.5mg/rat)injection.Three days later the animals were sacrificed and ovarian granulosa cells collected for isolation of DNA. Granulosa cells apoptosis was assessed by examining the pattern of fragmented DNA in cell lysates by gel electrophore- sis.Serum estradiol and progesterone levels were also determined.Hematoxylin and eosin stainning was per- formed for histological study.Results:Both mifepristone and testosterone increased the fragmentation of low mol wt DNA.In con- trast,tyrosine inhibited the fragmentation of DNA.Compared with the control group,estradiol levels in the mifepristone and testosterone treated groups decreased,while progesterone levels increased,but in the tyro- sine treated group the results was just the opposite.Morphologically,atretic follicles increased in mifepris- tone and testosterone treated groups and reduced in tyrosine treated group.Conclusions :These data suggested that tyrosine,mifepristone and testosterone play an important role in follicle atresia ,with mifepristone and testosterone promoting apoptosis and tyrosine inhibiting apoptosis.