脑梗死患者血清一氧化氮和一氧化氮合酶水平与脑血管反应性的关系

The relationship between nitric oxide/nitric oxide synthase in blood serun and cerebrovascular reactivity in patients with cerebral infarction

目的探讨脑梗死患者血清中一氧化氮(N0)和一氧化氮合酶(NOS)水平的变化对脑血管反应性(CVR)的影响。方法采用前瞻性病例对照研究,脑梗死组为发病2周内的颈内动脉系统脑梗死患者(193例),对照组为无脑梗死的体检者(103例)。对两组分别使用Griess重氮化反应法和酶标法,进行静脉血NO产物浓度及NOS活性检测;采用经颅多普勒超声结合屏气试验获取屏气指数(BHI)以评价CVR。结果脑梗死组和对照组的BHI分别为1.0±0.4和1.4±0.5,NO产物浓度中位数分别为6.04(3.83～11.49)、6.89(4.64～12.43)μmol/L,NOS活性分别为(3.0±1.5)、(3.2±1.5)U/ml。脑梗死组BHI及NO产物浓度均低于对照组(均P<0.05),BHI与NO产物浓度呈正相关(r=0.39,P=0.000),与NOS活性无相关性(r=0.168,P=0.454)。两组NOS活性差异无统计学意义(P=0.517)。结论脑梗死患者的CVR降低,与NO含量减少有一定相关性,但尚不能确定CVR与NOS活性的关系。NO可能是参与调节CVR的因素之一。

Objective To investigate the effect of nitric oxide （NO） and nitric oxide synthase （NOS） on cerebrovascular reactivity （CVR） in patients with cerebral infarction. Methods In the prospective case-control study, 193 patients with cerebral infarction in internal artery system within 2 weeks were used as cerebral infarction group, and 103 normal healthy subjects were used as control group. Griess diazotization assay and enzyme-labelled immunosorbent assay were used for measuring the concenration of NO product and NOS activity in both groups; the breath-holding index （BHI） was obtained by transcranial Doppler combined with breath-holding test to evaluate CVR. Results BHIs in the cerebral infarction and control groups were 1.0 ±0. 4 and 1.4 ±0. 5, respectively; the median concentration of NO product was 6.04 （3. 83 - 11.49） μmol/L and 6. 89 （4. 64 - 12. 43） μmol/L, respectively; NOS activity was 3.0 ± 1.5 U/mL and 3.2 ± 1.5 U/mL, respectively. BHI and the cocentration of NO production in the cerebral infartion group were lower than those in the control group （ all P 〈 0. 05 ）. BHI showed positive correlation with NO production （ r = 0. 39, P = 0. 000）, and there was no correlation with NOS. There was no NOS activity difference between the two groups （P = 0. 517 ）. Conclnsions There were certain correlations between the decrease of CVR in patients with cerebral infarction and the reduction of NO content, however, the relations between CVR and NOS activity remained uncertain. NO may be one of the factors in regulating CVR.