小鼠卵巢EGFR表达检测及EGF提高小鼠超数排卵效果研究

EGFR expression in ovary and superovulation efficiency by EGF injection in mouse

在检测发情周期不同阶段小鼠卵巢表皮生长因子受体(epidermal growth factor receptor,EGFR)表达的基础上,利用小鼠卵巢组织学、胚胎回收与胚胎体外培养方法,研究超数排卵前腹腔注射表皮生长因子(epidermal growth factor,EGF)对小鼠超数排卵效果的影响。结果显示:(1)EGFR在卵巢内主要定位于腔前卵泡、有腔卵泡的颗粒细胞和卵丘细胞,间情期、发情前期和发情期小鼠卵巢EGFR阳性反应均强于发情后期。(2)对发情前期和间情期小鼠按照每克体质量5、10、20、40ng的EGF进行腹腔注射,24h后注射孕马血清促性腺激素(pregnant mare serum gonadotropin,PMSG)进行超数排卵处理。发情前期小鼠在EGF注射后24h,卵巢切面已有较多的有腔卵泡分布,而间情期小鼠直到PMSG注射后24h,卵巢切面上才可观察到较多的腔前卵泡和有腔卵泡,且发情前期和间情期小鼠卵巢切面上有腔卵泡数量呈EGF剂量依赖性增多。(3)小鼠注射20ng/g EGF预处理24h,超排配种后见栓鼠的2-细胞胚胎回收数最高(P<0.05);当EGF剂量超过40ng/g时,胚胎回收数降低;发情前期各组小鼠2-细胞胚胎回收数均低于对应EGF注射剂量间情期小鼠组的。(4)各组2-细胞胚胎体外囊胚发育率无显著性差异(P>0.05)。研究结果表明,小鼠卵巢组织中EGFR定位于腔前卵泡、有腔卵泡的颗粒细胞和卵丘细胞,间情期、发情前期和发情期小鼠卵巢EGFR阳性反应均强于发情后期的;超排前24h腹腔注射20ng/g EGF,可获显著提高间情期和发情前期小鼠的超数排卵效果,并且不影响胚胎的发育潜能。

The effect of epidermal growth factor（EGF）on follicle development and superovulation efficiency was investigated by analysis of ovarian histology,embryo collection and in vitro culture,basing on the epidermal growth factor receptor（EGFR）expression pattern of mouse ovaries at different stages of estrous cycle.Results showed：（1）EGFR mainly localized in granulose cells or cumulus cells in preantral and antral follicles,the positive reaction of EGFR in ovaries of proestrus,oestrus and dioestrus mouse were stronger than that of metoestrus mouse.（2）Proestrus and dioestrus mice were treated with 5,10,20 and 40ng EGF per gram body weight（ng/g）,followed by superovulated with PMSG after 24 h.Antral follicles distributed in ovaries of proestrus mouse after 24 hof the EGF injection,while it was observed after 24 hof PMSG injection in dioestrus mouse.The number of antral follicles increased with adding EGF dosage.（3）The amount of 2-cell embryo of proestrus and dioestrus mice injected with 20ng/g EGF before superovulation was significant higher than that of control group,5and 10 ng/g EGF group（P 0.05）,it decreased when the EGF dosage reached 40ng/g and the number of dioestrus mouse was higher than that of proestrus mice with the same treatment.（4）There were no significant difference in blastocyst development rate in vitro of 2-cell embryo in all groups（P〈0.05）.These results demonstrated that EGFR mainly localized in granulose cells or cumulus cells in preantral and antral follicles,the positive reaction of EGFR in ovaries of dioestrus,proestrus and oestrus mouse were stronger than that of metoestrus mouse.Injecting with 20ng/g EGF 24 hbefore superovulation could significantly promote the superovulation efficiency of dioestrus and proestrus mouse,furthermore,it had no adverse impact on embryo developmental capacity.