哮喘患儿外周血一氧化氮、内皮素含量变化及临床意义

PLASMA NITRIC OXIDE AND ENDOTHELIN LEVELS IN ASTHMATIC CHILDREN AND THEIR CLINICAL SIGNIFICANEC

采用镉还原柱层析和比色法测定了４３例哮喘患儿外周血亚硝酸／硝酸根离子（ＮＯ＿２／ＮＯ＿３）水平，另用放射免疫法测定了内皮素（ＥＴ）和环磷酸鸟苷（ｃＧＭＰ）水平以及循环内皮细胞（ＣＥＣ）水平。结果：哮喘患儿血浆ＮＯ＿２／ＮＯ＿３，ｃＧＭＰ及ＣＥＣ水平均明显高于正常儿童，其中１１例重度哮喘患儿血浆ＮＯ＿２／ＮＯ＿３和ＣＥＣ水平较３２例轻中度哮喘患儿更高；轻、中度哮喘患儿血浆ＥＴ水平无明显变化，而重度哮喘患儿则明显升高；且血浆ＮＯ＿２－／ＮＯ＿３－与ｃＧＭＰ及ＣＥＣ水平呈显著性正相关，而与ＥＴ水平相关不显著。提示：哮喘时一氧化氮（ＮＯ）产生过多，发挥其细胞及组织毒性作用，使肺血管内皮细胞等损伤、脱落，从而引起和加重哮喘发病。且血浆ＥＴ及ＣＥＣ水平与哮喘病情密切相关。

We examined nitrite and nitrate (NO_2-/NO_3-),endothelin(ET),cGMP and circulating en- dothelial cells (CEC)levels in the plasma in 43 asthmatic children and 20 matched normal children。 The results showed that all asthmatic children had increased amounts of NO_2-NO_3- , cGMP and CEC com- pared with normal control subjects(P<0. 05～0. 001). Among them, ll severe asthmatic children(status asthmaticus ) had higher amounts of NO_2- /NO_3- and CEC than the 32 mild asthmatic children ( P < 0. 001 ). The 1l severe asthmatic children presented significantly higher levels of ET than normal subjects(P <0.00l ), while there was no significant alteration in mild asthmatic children (P> 0.05 ). Elevations of N0_2-/NO_3- were correlated with cGMP and CEC(P<0.01;0.05). The results suggests that there was increased production of nitric oxide(NO) in asthmatic children,and the NO produced could cause cytotoxi- city and mediate pulmonary vascular endothelial cell damage and scaling。 We conclude that the determina tion of circulating plasma levels of ET and CEC may be useful in forecasting the severity of illness。