大鼠延髓内雌激素β受体表达变化对延髓神经元结构和功能的影响

Effects of changes of estrogen receptor beta in medulla oblongata on the structure and function of medulla oblongata neurons in rats

目的:研究三羟基异黄酮与17-β雌二醇对大鼠延髓雌激素β受体表达的影响,探讨雌激素作用神经系统的机制。方法:30只去卵巢SD大鼠,随机分为去卵巢组(A组)、雌二醇组(B组)和三羟基异黄酮组(C组),手术后10d起分别皮下注射生理盐水0.1mL/d,17-β雌二醇20μg/(kg·d)、三羟基异黄酮200μg/(kg·d);10只假手术组(D组)大鼠,只切开腹膜不切除卵巢,手术后10d起每只动物皮下注射生理盐水0.1mL/d。各组动物连续用药6周后观察结果。结果:①血清雌二醇的浓度:A组(9.44±6.04)ng/L和C组(7.03±5.65)ng/L显著低于D组(19.41±8.37)ng/L,差异有非常显著性意义(t=2.97,3.77,P<0.01,),B组(15.52±8.54)ng/L与A组比较显著升高(t=2.74,P<0.01),而与D组比较差异无显著性意义。②A组与D组比较大鼠延髓ER-β免疫阳性细胞数量下降、阳性细胞总面积和平均吸光度降低(P<0.01)。切除卵巢后补充17-β雌二醇和三羟基异黄酮的大鼠延髓雌激素β受体表达明显增加,与A组比较延髓雌激素β受体免疫阳性细胞数量增加、阳性细胞总面积和平均吸光度升高(P<0.01),而与D组比较无统计学意义。结论:三羟基异黄酮和17-β雌二醇对延髓ER-β的表达有明显的调节作用,可能通过这一途径影响着延髓神经元的结构和功能。

AIM:To study the effects of genistein and 17-beta(β) estradiol on the expres sion of estrogen receptor beta(ER-β) in medulla oblongata of rats. METHODS:Thirty ovariectomized SD rats were randomly divided into ovariectomize d group(group A),estradiol group(group B) and genistein group(group C),the rat s in the three groups were subcutaneously injected with normal saline(0.1 mL per day),17-β estradiol(20 μg/kg per day) or genistein(200 μg/kg per day),resp ectively from the 10th day after operation,and another 10 rats in the sham opera tion group(group D),operated with no ovaries excision, received subcutaneous inj ection of normal saline(0.1 mL per day). The results were observed in all groups after successive medication for 6 weeks. RESULTS:①The levels of serum estradiol in group A[(9.44±6.04) ng/L] and grou p C[(7.03±5.65) ng/L] were significantly lower than that in group D[(19.41±8.3 7) ng/L](t=2.97,3.77,P< 0.01),and that in group B[(15.52±8.54) ng/L] was incr eased obviously as compared with that in group A(t=2.74,P< 0.01),but not signifi cantly different from that in group D.②The number of ER-β immune positive ce lls in medulla oblongata was decreased, the total area of positive cells and mea n absorbance(A) were reduced in group A as compared with those in group D(P< 0.0 1).The expression of ER-β in medulla oblongata was obviously increased in gro up B and group C,and compared with group A, the number of ER-β immune positiv e cells in medulla oblongata was increased, the total area of positive cells and mean A value were raised(P< 0.01), while there was no statistical significance as compared with those in group D. CONCLUSION:The genistein and 17-β estradiol can obviously regulate the expr ession of ER-β,which may has an effect on the structure and function of neuron s in medulla oblongata.