目的观察尾静脉注射不同剂量羟基红花黄色素A(HSYA)的缺血再灌注大鼠脑组织3-硝基酪氨酸(3-NT)、诱导型一氧化氮合成酶(iNOS)、NO表达变化。方法将健康雄性SD大鼠随机分为假手术组、模型组、低剂量HSYA组、中剂量HSYA组、高剂量HSYA组。假手术组仅手术暴露和分离颈总、颈内及颈外动脉,然后缝合;其余大鼠采用线栓法制备大脑中动脉闭塞再灌注(MCAO/R)模型。低、中、高剂量HSYA组大鼠缺血后60 min尾静脉注射2.5、5、10 mg/kg的HSYA;假手术组和模型组大鼠同时尾静脉注射相同体积Tris缓冲液。继续饲养24 h。采用Western blotting法检测各组大鼠缺血再灌注脑组织3-NT、iNOS相对表达量;采用Griess法检测各组大鼠缺血再灌注脑组织NO相对表达量。结果假手术组、模型组、低剂量HSYA组、中剂量HSYA组、高剂量HSYA组大鼠缺血再灌注脑组织3-NT条带灰度值分别为(2.81±1.37)×10~3、(46.86±4.75)×10~3、(44.51±4.13)×10~3、(13.88±2.98)×10~3、(6.38±2.66)×10~3;iNOS条带灰度值分别为(2.25±0.32)×10~3、(79.67±4.73)×10~3、(75.29±4.08)×10~3、(27.31±2.77)×10~3、(19.19±1.86)×10~3,模型组和低、中、高剂量HSYA组大鼠缺血再灌注脑组织NO表达量分别为(16.50±2.20)、(15.40±1.44)、(10.33±1.30)、(6.80±0.73)nmol/mg。模型组、低剂量HSYA组、中剂量HSYA组、高剂量HSYA组大鼠缺血再灌注脑组织3-NT、iNOS水平高于假手术组(P均〈0.05)。低剂量HSYA组大鼠缺血再灌注脑组织3-NT、iNOS、NO水平和模型组相比,P〉0.05。中、高剂量HSYA组大鼠缺血再灌注脑组织3-NT、iNOS、NO水平低于模型组和低剂量HSYA组(P均〈0.05),且高剂量HSYA组缺血再灌注脑组织3-NT、iNOS、NO水平低于中剂量HSYA组(P均〈0.05)。结论尾静脉注射不同剂量的HSYA可以抑制缺血再灌注大鼠脑组织3-NT、iNOS、NO表达,HSYA剂量越高?
Objective To observe the expression changes of 3-nitrotyrosine (3-NT), inducible nitric oxide synthase (iNOS), and nitric oxide (NO) in brain tissues of ischemia-reperfusion rats treated with different doses of hydroxysafflor yellow A (HSYA) by intravenous injection. Methods The healthy adult male SD rats were randomly divided into the sham operation group, model group, low-dose HSYA group, medium-dose HSYA group and high-dose HSYA group. In the sham operation group, rats" common carotid artery, internal carotid artery and external carotid artery were exposed, and then su- tured. The other rats were subjected to a 60-min middle cerebral artery occlusion and 24-h reperfusion (MCAO/R). The rats in the low-dose, medium-dose and high-dose HSYA groups were injected with 2.5, 5 and 10 mg/kg HSYA, respec- tively, in the tail vein at 60 min after ischemia, and the same volume of Tris buffer was injected into the tail vein of rats in sham operation group and model group. All rats were continued to raise for 24 h. The expression of 3-NT and iNOS in the rat brain tissues after ischemia-reperfusion in each group was examined by Western blotting. The NO level was also detected by Griess assay. Results The absolute gray values of 3-NT in the sham operation group, the model group, the low-dose HSYA group, the medium-dose HSYA group and the high-dose HSYA group after isehemia-reperfusion were (2.81 ± 1.37) xl03, (46.86±4.75) 103, (44.51 ±4.13) ×103, (13.88 ±2.98) ×103, and (6.38±2.66)×103, respec- tively ; the absolute gray values of iNOS of each group were ( 2.25 ± 0.32 )×103, ( 79.67 ± 4.73 ) ×103 , ( 75.29 ± 4.08) ×103 , (27.31 ±2.77) ×103, (19.19 ± 1.86)×103, respectively. In the model group and low-dose, medium- dose, and high-dose HSYA groups, the levels of NO were ( 16.50 ± 2.20) , ( 15.40 ± 1.44) , ( 10.33±1.30) , and ( 6.80 ± 0.73 ) nmol/mg. The levels of 3-NT, iNOS and NO in brain tissues of the model group, low-dose HSY