醛固酮对大鼠主动脉bax基因表达的影响

Effect of Aldosterone on bax Gene Expression in Rat Aorta

目的研究醛固酮对大鼠主动脉bax基因表达的影响。方法32只SD大鼠随机分为空白对照组、腺瘤组、腺瘤＋依普利酮组和腺瘤＋肼苯哒嗪组。在每只大鼠皮下埋植的微量渗透泵内注入空白溶剂或醛固酮。8周后通过免疫组化、RT—PCR和Western印迹检测主动脉bax基因的表达。结果与对照组相比，腺瘤组大鼠主动脉bax mRNA和蛋白表达都显著上调（P〈0．05）；依普利酮能够抑制醛固酮对bax基因的诱导作用（P〈0．05）；而肼苯哒嗪虽然可以使大鼠收缩压下降，但不能阻止醛固酮对bax基因的作用。结论醛固酮通过诱导bax基因表达，调节血管平滑肌细胞凋亡和干预细胞周期进程，可能是其导致血管重构的机制之一。

Objective To study the effect of aldosterone on expression of bax gene in rat aorta. Methods 32 Sprague-Dawley rats bearing an osmotic mini-pump that infuses vehicle or aldosterone （1 μg/h ）, were randomly divided into 4 groups： control; adenoma; adenoma plus eplerenone （100 mg/kg/day ） and adenoma plus hydralazine （25 mg/kg/day） . After 8 weeks, the expression of bax gene in the aorta was examined at both rnRNA and protein levels by immunohistochemistry, RT-PCR and Western blot. Results Compared with controls, the expression of bax mRNA and protein in the aorta was significantly upregulated in adenoma group （ P 〈 0. 05 ） . This upregulation was inhibited by eplerenone but not by hydralazine. Conclusion The upregulated bax gene by aldosterone via mineralocorticoid receptor independently of blood pressure, may be involved in aldosterone-induced vascular remodeling.