血小板活化因子和一氧化氮合酶在高原支气管哮喘发生中的作用

The levels of platelet-activating factor and nitric oxide synthase in bronchial asthma at high altitude

目的 探讨血小板数、血小板活化因子（platelet-activating factor,PAF）和一氧化氮合酶（nitric oxide synthase,NOS）对高原低氧环境中支气管哮喘（简称哮喘）发病的影响.方法 采用酶联免疫吸附法测定平原对照组、高原对照组、高原哮喘组和平原哮喘组血清PAF活性、总一氧化氮合酶（TNOS）、诱导型一氧化氮合酶（iNOS）和原生型一氧化氮合酶（cNOS）的活性,并进行血小板计数.计量资料用（-x）±s表示,组间均数差异的显著性分析采用单因素方差分析.相关性分析用Pearson直线相关分析法.结果 （1）高原对照组和高原哮喘组血小板数分别为（140±47）和（166±46）×109/L,低于平原对照组的（237±98）×109/L和平原哮喘组的（232±71）×109/L（均P＜0.01）.（2）哮喘组血清PAF浓度均高于对照组,平原哮喘组PAF浓度（877±297）pg/L不仅高于平原对照组（290±132）pg/L和高原对照组（223±82）pg/L,而且高于高原哮喘组（429±254）pg/L,各组总体间差异有统计学意义（F=66.08,P＜0.01）.血小板数和血清PAF活性间存在正相关（r=0.283,P＜0.01）.（3）不同海拔高度对照组TNOS、iNOS和cNOS活性比较差异无统计学意义;平原哮喘组TNOS、iNOS和cNOS水平[分别为（36.2±23.0）、（20.3±14.7）和（15.9±8.4）U/ml]明显高于高原对照组[（11.9±1.3）、（9.4±1.5）和（4.9±0.5）U/ml]和高原哮喘组[（21.0±2.3）、（15.4±2.5）和（5.3±0.8）U/ml],均P＜0.01,主要以iNOS增高为主.4组TNOS、iNOS和cNOS水平总体差异有统计学意义（F值分别为17.197、8.258和34.250,均P＜0.01）.结论 PAF和NOS活性降低可能是高原地区哮喘患病率低的原因之一.

Objective To investigate levels of platelet- activating factor （PAF） and nitric oxide synthase（ NOS） in plateau asthma. Methods Peripheral blood platelet was counted and the serum level of PAF,TNOS,iNOS and cNOS were measured by ELISA in patients with asthma who lived at plateau and at plain respectively and healthy volunteers as the plan control group and in plateau control group. The data were expressed as （x） ± s, and one way ANOVA was used for comparison of means; The correlation of 2 variables was estimated by Spearson rank correlation coefficience. Results The PLT count was （166 ± 46） ×109/L in the plateau asthma group and（140 ±47）× 109/L in the plateau control group, and both were significantly lower than those of the plain control group [ （237 ±98） × 109/L] and the plan asthma group [ （232 ±71） ×109/L, P 〈0. 01 ]. The levels of serum PAF in the asthma groups were higher than those of the control groups. The level of serum PAF in the plan asthma group [ （877 ±297）pg/L], was not only higher than that in the plan control group [ （290 ± 132） pg/L] ,but also higher than that in the plateau asthma group[ （429 ±254）pg/L] ; the difference being significant among groups（F = 66.08, P〈0.01）. The PLT count showed a positive correlation with the level of PAF（ r = 0. 283, P 〈 0. 01）. The levels of TNOS, iNOS, and cNOS were not statistically different （P 〉0. 05） between the plain control group and the ntrol group. The levels of TNOS, iNOS and cNOS in plain asthmatic group [ （36. 2 ± 23. 0）, （20. 3 ± 14. 7） and （15. 9 ± 8.4） U/ml respectively] were significantly higher than those of the plateau control [（11. 9 ±1.3）, （9.4 ±1.5） and （4.9 ±0.5） U/ml] and the plateau asthmatic [（21.0 ±2. 3）, （15.4±2.5） and （5.3±0.8） U/ml] groups（F =17.197, 8.258, 34.250, respectively, P〈0.01）. The increase of iNOS level was more significant Conclusion Asthma in plateau area is associated with decrease of the levels of PLT, PAF and NOS.