IGF-I和IGF-I受体在早孕期大鼠子宫中的表达及意义

Expression of IGF-I and Its Receptor in the Uterus of Rat and the Relationships with Progesterone during Peri-implantation

目的 :探讨类胰岛素样生长因子 - I(IGF- 1 )和 IGF- I受体 (IGF- IR)在围着床期大鼠子宫内膜和胚胎滋养层细胞中的表达、意义及其与孕激素 (P)的关系。方法 :收集自然交配的孕 3～ 1 0 d大鼠的血清及子宫组织 ,以动情期雌鼠为对照。采用放射免疫法测定大鼠血清 P水平 ;免疫组化Ls AB法检测 IGF- I、IGF- IR及孕激素受体 (PR)在孕早期大鼠子宫内膜及胚胎滋养层细胞中的表达 ,计算机图像分析法进行定量。结果 :IGF- I及其受体在大鼠内膜腺、腔上皮 ,蜕膜细胞及滋养层细胞中均有表达。IGF- I在大鼠子宫内膜中的表达强度随孕天逐渐升高 ,孕 5～ 7d达到最强 ,此后降到动情期水平 ,与 P及 PR无显著性相关。IGF- IR的表达强度随孕天降低 ,孕 5～ 6 d达到最小值 ,孕 8～ 1 0 d又上升到动情期水平 ,与 P及 PR均呈显著性负相关 (P<0 .0 5 )。IGF- I和 IGF-IR在孕 8～ 1 0 d大鼠滋养层细胞中的表达强度随孕天逐渐升高 ,与血 P及 PR均无显著性相关。结论 :IGF- I与 IGF- IR在围着床期大鼠子宫内膜中的表达出现分离 ,既抑制了 IGF- I对子宫内膜过强的促生长作用 ,使之蜕膜化 ;同时又满足了孕早期胚胎生长发育所需的较高 IGF- I水平 ,此效应主要受 P调节。 P和 IGF- I对胚胎滋养层细胞功能的调节可能是独立进行的。

Objective: To study the expression of insulin-like growth factor(IGF-I) and its receptor in the endometrium and trophoblast cell of rat and its correlation with progesterone(P) during peri-implantation.Metheds: To establish the pregnant model,rat the serum,uterine tissue at 3～10 day of pregnancy was used and the rat in estrus was used as control.The serum P level was determined by radioimmunoassay.The expression of IGF-I,IGF-I receptor(IGF-IR) and P receptor (PR) in the endometrium and trophoblast cell of rat was detected by histoimmunochemistry and quantified by computer image analysis.Results: IGF-I and its receptor expressed in luminal and glandular epithelium,decidual cell and trophoblast cell.PR was located in same cells as IGF-I and IGF-IR.Showing no significant correlation with P and PR,the intensity of IGF-I expression in endometrium decreased with pregnancy date and reached rock bottom at 9 day of pregnancy.The intensity of IGF-IR expression in endometrium appeared like a trough and reached bottom during 5～7 day of pregnancy and showed negative significant correlation with P and PR(P<0.05).The intensity of IGF-I and IGF-IR expression in trophoblast cell rised with pregnancy date during 8 to 10 day of pregnancy and showed no significant correlation with serum P and PR.Conclusion: The action of P that down-regulated IGF-IR expression while had no effect on IGF-I expression suppresses the over-proliferate effect of IGF-I on endometrium.As a result,allows decidualization of endometrium and satisfies urge requirement of IGF-I for embryo growth and development.P and IGF-I also have some roles in modulation of trophoblast function independently.