二苯乙烯苷的雌激素样作用及其对性未成熟小鼠子宫ER表达的影响

目的:探讨二苯乙烯苷(TSG)的雌激素样作用,以及其对性未成熟小鼠子宫雌激素受体(ER)表达的影响。方法:将60只性未成熟雌性昆明种小鼠随机分为正常组,阳性对照组(戊酸雌二醇,0.18 mg/kg),TSG低、高剂量组(50、150 mg/kg),TSG低、高剂量+戊酸雌二醇组(剂量同单用组)。正常组小鼠灌胃等体积水,各给药组小鼠灌胃相应药物溶液0.2 mL/10 g,早晚各1次,连续5d。末次给药次日,测定并计算各组小鼠子宫指数和体质量增幅;采用酶联免疫吸附测定法检测其血清雌激素雌二醇(E_2)、黄体生成素(LH)、卵泡雌激素(FSH)]含量;采用苏木精-伊红染色法观察其子宫组织形态学特征,并检测子宫管径和子宫内膜厚度;采用免疫组织化学染色法检测其子宫组织中ER(ER-α、ER-β)的表达水平。结果:正常组小鼠子宫肌层排列平行、紧密,子宫上皮呈单层柱状,ER-α、ER-β表达较少;各给药组小鼠子宫管径、内膜及上皮均不同程度地增大、增厚或增生,ER-α、ER-β表达有所变化。与正常组比较,各给药组小鼠子宫指数(阳性对照组、TSG高剂量组、TSG各剂量+戊酸雌二醇组)、体质量增幅(阳性对照组、TSG高剂量组、TSG低剂量+戊酸雌二醇组)、子宫管径及内膜厚度(阳性对照组、TSG低剂量组、TSG各剂量+戊酸雌二醇组)、ER-α的表达量(阳性对照组、TSG各剂量+戊酸雌二醇组)、ER-β的表达量(阳性对照组、TSG高剂量组+戊酸雌二醇联用组)均显著升高,血清LH(阳性对照组、TSG高剂量组)、FSH(TSG低剂量+戊酸雌二醇组)水平均显著降低(P<0.05或P<0.01);TSG各剂量+戊酸雌二醇组小鼠子宫指数、子宫管径及内膜厚度、ER-α及ER-β的表达量以及TSG低剂量+戊酸雌二醇组小鼠体质量增幅、血清E_2含量均显著高于TSG同剂量单用组(P<0.05或P<0.01);TSG各剂量组小鼠子宫指数、子宫管径及内膜厚度、ER-α及ER-β的表达量,TSG各剂量+戊酸雌二醇组小鼠子宫管径、ER-β的表达量以及TSG低剂量组小鼠体质量增幅均显著低于阳性对照组,而TSG各剂量+戊酸雌二醇组小鼠血清LH水平均显著高于阳性对照组(P<0.05或P<0.01)。结论:TSG可一定程度地增加性未成熟小鼠的子宫指数和体质量,并调节其体内雌激素水平,增加子宫管径及内膜厚度,上调子宫组织中ER的表达,具有一定的雌激素样作用。但这种作用弱于戊酸雌二醇,且两者联合使用可能会拮抗戊酸雌二醇的作用。

Estrogen-like Effect of Tetrahydroxy Stilbene Glucoside and Its Effects on the Expression of ER in Uterus of Sexually Immature Mice

OBJECTIVE:To investigate estrogen-like effect of tetrahydroxy stilbene glucoside (TSG) and its effects on the expression of estrogen receptor (ER) in uterus of sexually immature mice. METHODS:Totally 60 sexually immature Kunming mice were randomly divided into normal group,positive control group (estradiol valerate,0.18 mg/kg),TSG low-dose and high-dose groups(50,150 mg/kg),TSG low-dose and high-dose groups+estradiol valerate groups(same dose as medication alone group). Normal group was given constant volume of water intragastrically,and administration groups were given relevant medicine 0.2 mL/10 g,once morning and night,for consecutive 5 d. The uterus index and body weight increase of mice in each group were determined and calculated the next day after the last administration. The contents of serum estrogen(E2,LH,FSH)were determined by ELISA. HE staining was used to observe the morphology characteristics of uterus,and uterine tube diameter and endometrial thickness were detected. The expression of ER (ER-α and ER-β) in uterus was detected by immunohistochemical staining. RESULTS: The myometrium of the mice in normal group was parallel and compact,the epithelium of the uterus was columnar,and the expression of ER-α and ER-β was low. The uterine tube diameter, endometrium and epithelium of mice in each administration group increased,thickened or proliferated in varying degrees,and the expression of ER-α and ER-β changed. Compared with normal group,uterus indexes (positive control group,TSG high-dose group,TSG+estradiol valerate groups),the increase of body weight(positive control group,TSG high-dose groups, TSG low-dose+estradiol valerate group),uterine tube diameter and endometrial thickness(positive control group,TSG low-dose group,TSG+estradiol valerate groups),the expression of ER-α(positive control group,TSG+estradiol valerate groups)and the expression of ER-β(postive control group,TSG high-dose + estradiol valerate group)were increased significantly,while serum contents of LH(positive control group,TSG high-dose group)and FSH(TSG low-dose+estradiol valerate group)were decreased significantly(P<0.05 or P<0.01). The uterus index,uterine tube diameter,endometrial thickness and the expression in ER-α and ER-β of TSG+estradiol valerate groups,the increase of body weight and serum content of E2 in TSG low-dose+estradiol valerate group were significantly higher than same TSG dose alone groups(P<0.05 or P<0.01). The uterus index,uterine tube diameter, endometrial thickness and the expression of ER-α and ER-β in TSG groups,uterine tube diameter and the expression of ER-β in TSG+estradiol valerate groups,body weight increase of mice in TSG low-dose group were significantly lower than positive control group,while serum content of LH in TSG+estradiol valerate groups were significantly higher than positive control group(P<0.05 or P<0.01). CONCLUSIONS:TSG can increase uterus indexes and body weight of sexually immature mice to certain extent, regulate estrogen level,increase the diameter of uterine tube and endometrial thickness and up-regulate the expression of ER in the uterus,showing certain estrogen-like effect,which is weaker than that of estradiol valerate. Combined use of them may antagonize the effect of estradiol valerate.