肾血管性高血压对诱导型一氧化氮合酶表达及活性的影响

Effect of renovascular hypertension on activity and expression of inducible nitric oxide synthase

目的 :通过测定肾血管性高血压大鼠血管及肾组织诱导型一氧化氮合酶 (i NOS)活性及表达的变化情况 ,探讨血压与 i NOS间的关系。方法 :运用肾动脉不全结扎方法制备 SD大鼠肾血管性高血压模型 ,并应用Greiss反应、L 精氨酸同位素标记法及 Western blot等分别测定一氧化氮的终产物——尿中 NO- 2 / NO- 3(U NOx)的生成、i NOS活性和 i NOS蛋白水平。结果 :SD大鼠肾动脉狭窄术后 ,其 UNOx水平显著升高 ,术后 1周由术前的 (2 30 7.3± 486 .6 ) nm ol/ 2 4h增加到 (5 45 1.4± 795 .2 ) nm ol/ 2 4h。术后 4周其主动脉及肾组织 (包括肾皮质及髓质 ) i NOS活性均较正常对照组大鼠明显升高。 Western蛋白印迹显示 :肾血管性高血压大鼠主动脉 i NOS蛋白表达较对照组升高 2 36 .7% ,但没有观察到肾髓质 i NOS蛋白表达的变化。结论 :i NOS是血流动力学调控的重要组成部分 ;肾血管性高血压情况下 ,i NOS具有重要的代偿调节作用 ;血压升高是刺激 i

Objective:To investigate the relationship between arterial pressure and expression as well as activity of inducible nitric oxide synthase (iNOS).Methods:The renovascular hypertension was reproduced by renal artery stenosis in Spraugue Dawley (SD) rats.Levels of UNOx,activity and protein expression of iNOS were measured by Greiss reaction,the conversion rate of isotopelabelled Larginine to citrulline and Western blot respectively.Results:Following renal artery stenosis,UNOx,an index of the nitric oxide(NO) production of the whole body,significantly increased at one week after operation ( P <0 01),it increased to (5 451 4±795 2)nmol/24 h from(2 307 3±486 6)nmol/24 h prior to operation.It was also observed that the iNOS activity significantly increased in aorta and renal tissues including cortex and medulla of renovascular hypertensive rats compared with controls.Western blot showed iNOS expression was higher in aorta (236 7%),but not in renal medulla of renovascular hypertensive rats than that of controls.Conclusions:iNOS/NO pathway plays an important role in regulation of arterial pressure in renovascular hypertension.iNOS could be activated in case of hypertension by a pressurerelated mechanism.