大鼠肾脏α_1-肾上腺素受体和血管紧张素Ⅱ受体亚型表达水平随增龄的改变  

Changes in Expression of α_1-adrenergic Receptor and AngiotensinⅡ Receptor Subtypes in Kidney of Rats with Aging

作　　者：曹晓菁[1] 李艳芳[1] 

机构地区：[1]首都医科大学附属北京安贞医院心内科

出　　处：《首都医科大学学报》2008年第6期728-731,共4页Journal of Capital Medical University

基　　金：北京市自然科学基金(7042056)资助项目~~

摘　　要：目的研究α1-肾上腺素受体(α1-adrenergic receptor,α1-AR)和血管紧张素Ⅱ受体(angiotensinⅡreceptor,ATR)各亚型在增龄过程中蛋白水平的变化。方法采用蛋白质免疫印迹(Western blotting)分别对3月龄(青年组)、12月龄(中年组)、18月龄(老年前期组)和24月龄(老年组)Wistar大鼠肾脏α1-AR和ATR亚型蛋白水平进行测定。结果在α1-AR的亚型中,α1A-AR的表达水平随增龄逐渐下调(P<0.01);α1B-AR和α1D-AR的表达在各年龄组差异无统计学意义。在ATR的亚型中,AT1R表达水平在老年前期组和老年组均较青年组显著下调(P<0.01),中年组与青年组相比差异无统计学意义;AT2R的表达水平在老年组较青年组显著上调(P<0.01),青年组、中年组和老年前期组之间差异无统计学意义。结论肾脏α1-AR和ATR的表达水平随增龄而变化,α1A-AR的下调可能与肾脏在衰老过程中的功能减退相关;AT1R下调可能有利于肾脏在衰老过程中维持其正常的生理功能;AT2R在老年期表达上调,有利于拮抗AT1R的作用、消除随增龄出现的血管收缩功能增强的不利影响。Objective The changes in α1-adrenergic receptor（ α1-AR） and angiotensin Ⅱ receptor （ATR） expressions were considered to be associated with functional dechne of renal vasoconstriction, renal structure and function. This study was designed to examine the expressions of α1-AR and ATR subtypes in renal tissue from young adult, middle age, presenium to senium of rats. Methods Western blotting was used to quantitate the protein levels of α1-AR and ATR subtypes in renal tissue of 3-（ young adult）, 12-（ middle age）, 18-（presenium） and 24-（senium） month-old Wistar rats. Results α1A-AR expression decreased gradually with aging： α1A-AR protein levels decreased in middle age, presenium and senium when compared with young adult rats, respectively（P 〈 0.01 ）. However, the expressions of α1B-AR and α1D-AR remained unchanged during senescence. AT1R expressions were unaffected by aging from young adult to middle age, but exhibited a remarkable downregulation in presenim and senium（P 〈 0.01 ）. In addition, AT2R expression increased significantly in senium（P 〈 0.01 ）. Conclusion There are considerable changes in expression levels of renal α1-AR and ATR subtypes during aging. The downregulation of α1A-AR expression may account for the reduced reactivity of renal α1-AR to vasoconstrictors and the decline of renal function in senium. Both the downregulation of ATI R and the upregulation of AT2 R can be beneficial to maintain the normal physiological function of kidney during aging.

关 键 词：Α1-肾上腺素受体 血管紧张素Ⅱ受体 亚型 肾脏 增龄 

分 类 号：R544.14[医药卫生—心血管疾病]