目的:观察雌激素对大鼠肠系膜动脉平滑肌ATP敏感性钾离子通道 (KATP 通道)mRNA表达的影响,探讨KATP通道在雌激素调节大鼠肠系膜血管反应性中的作用.方法:雌性SD大鼠48只,体重(100±10) g,随机分为假手术组(sham)、卵巢切除组(Ovx)和卵巢切除后补充雌激素组(Ovx +E).采取实时荧光定量PCR检测大鼠肠系膜动脉中KATP通道mRNA的表达;观察各组大鼠肠系膜动脉对去甲肾上腺素(NE)升压效应的反应性.结果:与sham组相比,Ovx组大鼠肠系膜动脉KATP 通道的Kir6.1及SUR2B亚单位mRNA表达减少(P<0.05),而Ovx+E组则表达增加(P<0.05).与sham组相比,Ovx组大鼠的血管反应性明显增加(P<0.05),Ovx+E组无明显差异.给予KATP通道阻滞剂格列本脲后,sham组和Ovx+E组的动脉反应性增加(P<0.05),Ovx组无明显变化(P>0.05),此时3组间比较无明显差异(P>0.05).结论:雌激素可能通过上调肠系膜动脉平滑肌细胞KATP通道的表达来降低动脉对去甲肾上腺素升压效应的反应性.%AIM: To observe the expression of ATP - sensitive potassium ( KATP ) channel mRNA in mesenter-ic artery smooth muscle of rats with estrogen administration, and to evaluate the role of KATP channel in the effects of estrogen on the reactivity of mesenteric artery in rats. METHODS: Forty — eight female Sprague — Dawley rats, weighing ( 100 ± 10 ) g, were randomly divided into 3 groups: sham operation ( sham ) group, ovariectomy ( Ovx ) group and ovariectomy with estrogen administration ( Ovx + E ) group. The mRNA expression of KATP subunits in mesenteric artery smooth muscle was detected by quantitative real — time PCR. Artery reactivity in the rats was observed by norepinephrine — induced pressor response. RESULTS: Compared with sham group, the mRNA expression of Kir6. 1 and SUR2B was significantly decreased in Ovx group ( P < 0. 05 ), but increased in Ovx + E group ( P < 0. 05 ). Compared with sham group and Ovx + E group, the pressor response induced by norepinephrine in the rats were enhanced in Ovx group ( P <0. 05 ). No significant difference between sham group and Ovx + E group was observed. After administered with glibenclamide ( a KATP channel blocker ), the pressor response induced by norepinephrine was enhanced in sham group and Ovx + E group, and no changes in Ovx group. Meanwhile, no difference among the 3 groups was found. CONCLUSION: Estrogen up - regulates the expression of KATP channel subunits, which may be involved in estrogen — reduced pressor response to norepinephrine.
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