戊酸雌二醇对去卵巢大鼠下丘脑视前区肾上腺素能受体表达的影响

Effect of estradiol valerate on expression of adrenergic rceptors in the preoptic area of hypothalamus of ovariectomized rats

目的围绝经期潮热发生涉及诸多理论,其中神经递质机制的研究备受关注。文章观察去卵巢大鼠应用戊酸雌二醇处理4周后肾上腺素能受体α1和α2在大鼠下丘脑视前区表达的变化,为围绝经期潮热发生的中枢神经递质机制提供依据。方法雌性SD大鼠30只随机数字表法分为去卵巢组(OVX组)、假手术组、OVX后戊酸雌二醇处理(OVX+E2)组,各10只。无菌条件下进行手术。假手术大鼠只打开盆腔找到卵巢,并未将其切除;OVX组和(OVX+E2)组大鼠行双侧卵巢切除术,OVX组等渗盐水灌胃(10mg/kg)(,OVX+E2)组行戊酸雌二醇灌胃(0.8mg/kg)。麻醉、心脏灌注、取脑后制作石蜡切片。免疫组化法观察各组大鼠下丘脑视前区肾上腺素α1受体和肾上腺素α2受体的表达。结果免疫组化显示,OVX组大鼠下丘脑视前区肾上腺素α1受体细胞数[(54.0±3.9)个/100μm^2]低于假手术组[(66.3±4.0)个/100μm^2]、α2受体细胞数[(89.0±2.4)个/100μm^2]高于假手术组([71.0±2.2)个/100μm^2],差异有统计学意义(P<0.01),(OVX+E2)组α1受体细胞数[(63.7±4.5)个/100μm^2]高于OVX组,α2受体细胞数([73.1±3.5)个/100μm^2]低于OVX组(P<0.01)。结论肾上腺能α1、α2受体在去卵巢大鼠下丘脑视前区的表达发生变化,中枢去甲肾上腺素系统可能参与围绝经期潮热的发生。

Objective The occurrence of perimenopausal hot flashes involves many theories,among which the study of neurotransmitter mechanism has attracted much attention. This study aims to investigate the changes of α1 and α2 adrenoreceptors in the preoptic area of the hypothalamus(POAH)in ovariectomized rats after 4 weeks treatment with estradiol valerate,and explore the potential neurotransmitter mechanism of perimenopausal hot flashes. Methods 30 female Sprague-Dawley rats,weighing 230±10 g and aged 6-8WK,were divided into three groups:ovariectomy(OVX)group ,sham group,and ovariectomy plus estradiol valerate (OVX+E2)group,each 10. Rats in sham-operated group opened pelvic cavity to find ovaries,but did not remove them. The other rats underwent bilateral ovariectomy under sterile conditions. Rats in OVX group and(OVX+E2) group received bilateral ovariectomy, rats in OVX group received isotonic saline gavage(10 mg/kg),and rats in(OVX+E2)group received estradiol valerate gavage(0.8 mg / kg). Anesthesia,cardiac perfusion and paraffin section were made after taking the brain. The expression of α1 and α2 adrenoreceptors in POAH of the rats was detected by immunohistochemistry. Results After 4 weeks’treatment,the number of α1[(54.0±3.9)/100μm^2]and α2[(89.0±2.4)/100μm^2]adrenoreceptor positive cells in POAH of OVX group significantly decreased compared with that in sham group[(66.3±4.0)、(71.0±2.2)/100μm^2](P<0.01),while the number of α1 and α2[(63.7±4.5)、(73.1±3.5)/100μm^2)]adrenoreceptor positive cells in POAH of(OVX+E2 )group significantly increased compared with that in OVX group(P<0.01). The difference was statistically significant. Conclusion The expression of two adrenergic receptors in the POAH of ovariectomized rats changed. The central noradrenergic system may be involved in the mechanism of perimenopausal hot flashes,which need further studying.