目的:探讨Tempol对脑小血管病变卒中发生的影响。方法:以卒中易感型自发性高血压大鼠(SHRSP)为脑小血管病动物模型,将其随机分为对照组与Tempol处理组,每组10只。利用行为学观察评估卒中事件的发生率及大鼠的存活率,Elisa法测定额叶皮...目的:探讨Tempol对脑小血管病变卒中发生的影响。方法:以卒中易感型自发性高血压大鼠(SHRSP)为脑小血管病动物模型,将其随机分为对照组与Tempol处理组,每组10只。利用行为学观察评估卒中事件的发生率及大鼠的存活率,Elisa法测定额叶皮层丙二醛(MDA)的含量、总抗氧化能力(TAC)及超氧化物歧化酶(SOD)的活性,Evans blue染色测定血脑屏障的破坏程度,Western Blot测定紧密连接蛋白occludin、claudin-5与Zo-1的表达。结果:与对照组相比,Tempol处理组首次卒中发病时间推迟(36 d vs 20 d,P<0.05),卒中发病率下降(75%vs 100%,P<0.05),存活率提高(45%vs 25%,P<0.05)。Tempol处理组额叶皮层MDA含量(nmol/mg)降低(0.63±0.04 vs1.23±0.07,P<0.05),TAC与SOD酶活性(U/mg)增加(25.6±3.4 vs 15.6±1.2,P<0.05;7.46±0.92 vs 5.2±0.7,P<0.05)。Tempol处理组额叶皮层Evans blue含量(μg/mg)降低(3.75±0.42 vs 6.16±0.34,P<0.05),且伴有occludin、claudin-5与Zo-1蛋白表达增加。结论:Tempol可通过抑制氧化应激,减轻血脑屏障破坏,降低大鼠脑小血管病卒中发生风险。展开更多
AIM To determine the effect of tempol in normal rats fed high salt on arterial pressure and the balance between antagonist components of the renal renin-angiotensin system.METHODS Sprague-Dawley rats were fed with 8% ...AIM To determine the effect of tempol in normal rats fed high salt on arterial pressure and the balance between antagonist components of the renal renin-angiotensin system.METHODS Sprague-Dawley rats were fed with 8% NaCl high-salt （HS） or 0.4% NaCl （normal-salt, NS） diet for 3 wk, with or without tempol （T） （1 mmol/L, administered in drinking water）. Mean arterial pressure （MAP）, glomerular fltration rate （GFR）, and urinary sodium excretion （UVNa） were measured. We evaluated angiotensin Ⅱ （Ang Ⅱ）, angiotensin 1-7 （Ang 1-7）, angiotensin converting enzyme 2 （ACE2）, mas receptor （MasR）, angiotensin type 1 receptor （AT1R） and angiotensin type 2 receptor （AT2R） in renal tissues by immunohistochemistry.RESULTSThe intake of high sodium produced a slight but signifcant increase in MAP and differentially regulated components of the renal renin-angiotensin system （RAS）. This included an increase in Ang Ⅱ and AT1R, and decrease in ACE-2 staining intensity using immunohistochemistry. Antioxidant supplementation with tempol increased natriuresis and GFR, prevented changes in blood pressure and reversed the imbalance of renal RAS components. This includes a decrease in Ang Ⅱ and AT1R, as increase in AT2, ACE2, Ang （1-7） and MasR staining intensity using immunohistochemistry. In addition, the natriuretic effects of tempol were observed in NS-T group, which showed an increased staining intensity of AT2, ACE2, Ang （1-7） and MasR.CONCLUSION These findings suggest that a high salt diet leads to changes in the homeostasis and balance between opposing components of the renal RAS in hypertension to favour an increase in Ang Ⅱ. Chronic antioxidant supplementation can modulate the balance between the natriuretic and antinatriuretic components of the renal RAS.展开更多
文摘目的:探讨Tempol对脑小血管病变卒中发生的影响。方法:以卒中易感型自发性高血压大鼠(SHRSP)为脑小血管病动物模型,将其随机分为对照组与Tempol处理组,每组10只。利用行为学观察评估卒中事件的发生率及大鼠的存活率,Elisa法测定额叶皮层丙二醛(MDA)的含量、总抗氧化能力(TAC)及超氧化物歧化酶(SOD)的活性,Evans blue染色测定血脑屏障的破坏程度,Western Blot测定紧密连接蛋白occludin、claudin-5与Zo-1的表达。结果:与对照组相比,Tempol处理组首次卒中发病时间推迟(36 d vs 20 d,P<0.05),卒中发病率下降(75%vs 100%,P<0.05),存活率提高(45%vs 25%,P<0.05)。Tempol处理组额叶皮层MDA含量(nmol/mg)降低(0.63±0.04 vs1.23±0.07,P<0.05),TAC与SOD酶活性(U/mg)增加(25.6±3.4 vs 15.6±1.2,P<0.05;7.46±0.92 vs 5.2±0.7,P<0.05)。Tempol处理组额叶皮层Evans blue含量(μg/mg)降低(3.75±0.42 vs 6.16±0.34,P<0.05),且伴有occludin、claudin-5与Zo-1蛋白表达增加。结论:Tempol可通过抑制氧化应激,减轻血脑屏障破坏,降低大鼠脑小血管病卒中发生风险。
基金Supported by A grant from the Universidad de Buenos Aires(UBACYT 20020130200105BA)
文摘AIM To determine the effect of tempol in normal rats fed high salt on arterial pressure and the balance between antagonist components of the renal renin-angiotensin system.METHODS Sprague-Dawley rats were fed with 8% NaCl high-salt （HS） or 0.4% NaCl （normal-salt, NS） diet for 3 wk, with or without tempol （T） （1 mmol/L, administered in drinking water）. Mean arterial pressure （MAP）, glomerular fltration rate （GFR）, and urinary sodium excretion （UVNa） were measured. We evaluated angiotensin Ⅱ （Ang Ⅱ）, angiotensin 1-7 （Ang 1-7）, angiotensin converting enzyme 2 （ACE2）, mas receptor （MasR）, angiotensin type 1 receptor （AT1R） and angiotensin type 2 receptor （AT2R） in renal tissues by immunohistochemistry.RESULTSThe intake of high sodium produced a slight but signifcant increase in MAP and differentially regulated components of the renal renin-angiotensin system （RAS）. This included an increase in Ang Ⅱ and AT1R, and decrease in ACE-2 staining intensity using immunohistochemistry. Antioxidant supplementation with tempol increased natriuresis and GFR, prevented changes in blood pressure and reversed the imbalance of renal RAS components. This includes a decrease in Ang Ⅱ and AT1R, as increase in AT2, ACE2, Ang （1-7） and MasR staining intensity using immunohistochemistry. In addition, the natriuretic effects of tempol were observed in NS-T group, which showed an increased staining intensity of AT2, ACE2, Ang （1-7） and MasR.CONCLUSION These findings suggest that a high salt diet leads to changes in the homeostasis and balance between opposing components of the renal RAS in hypertension to favour an increase in Ang Ⅱ. Chronic antioxidant supplementation can modulate the balance between the natriuretic and antinatriuretic components of the renal RAS.
