目的：　探讨一氧化氮(NO)、脂质过氧化物(LPO)、血栓素B2 (TXB2 )、循环内皮细胞(CEC)在小儿哮喘及肺炎支原体(MP)肺炎中的作用。方法：　分别检测36例小儿哮喘、40例MP肺炎患儿及15例健康体检儿血NO,LPO,TXB2及CEC水平。结果：　小儿哮喘及MP肺炎急性期血NO,LPO,TXB2,CEC4项指标分别为:哮喘组(162 .27±36.12) μmol/L ,(8.62± 0.87)nmol/ml,(22 9.11± 64.75) pg/ml,(6.13± 1.15)n/0.9μl;MP肺炎组(95.52±33.84)μmol/L ,(5.76± 0 .53)nmol/ml,(388.72±80 .09) pg/ml,(6.36±1.02)n/0 .9μl,分别与对照组 [(68.57±13.80 ) μmol/L ,(4.62± 1.80 )nmol/ml,(105.76±20.10)pg/ml,(4.40±1.04)n/0 .9μl]相比,均增高显著,差异有显著性意义(P<0.01)。其中哮喘组血中NO ,LPO较MP肺炎组增高显著(P<0.01);MP肺炎组TXB2 较哮喘组增高明显 (P<0.01)。恢复期两种疾病所有指标均降低,TXB2,LPO已降至正常范围,而NO ,CEC在两周后[哮喘组(82.64±20.56)μmol/L,(5.41±1.29)n/0.9μl,MP肺炎组 (86.12±21.34)μmol/L,(5.57±1.12 )n/0 .9μl]仍高于正常对照组(P<0.05或0.01)。结论：　本研究提示

OBJECTIVE: To study the roles of nitric oxide (NO) and oxygen free radical (OFR) in the pathogenesis in children with asthma or Mycoplasma (MP) pneumonia. METHODS: The levels of NO, lipid peroxidation (LPO), thromboxane B 2 (TXB 2) and circulating endothelial cells (CEC) were detected in 36 children with asthma (asthma group), 40 MP pneumonia children (MP group) and 15 normal children (control group). RESULTS: The levels of NO, LPO, TXB 2 and CEC in the acute period in the asthma group [( 162.27 ± 36.12 ) μmol/L,( 8.62 ±0.87 ) nmol/ml,( 229.11 ± 64.75 ) pg/ml and ( 6.13 ± 1.15 ) n/ 0.9 μl , respectively] and in the MP group [( 95.52 ± 33.84 ) μmol/L,( 5.76 ± 0.53 ) nmol/ml,( 388.72 ± 80.09 ) pg/ml and ( 6.36 ± 1.02 ) n/ 0.9 μl , respectively] were significantly higher than those in the control group [( 68.57 ± 13.80 ) μmol/L,( 4.62 ± 1.80 ) nmol/ml,( 105.76 ± 20.10 ) pg/ml and ( 4.40 ± 1.04 ) n/ 0.9 μl , respectively](P< 0.01 ). The levels of NO and LPO in the asthma group were much higher thanthose in the MP group (P< 0.01 ), while the TXB 2 level was higher in the MP group than that in the asthma group(P< 0.01 ). The above 4 index levels decreased both in the asthma and MP groups in the recovery period. Of them, the TXB 2 and LPO levels were lowered to normal, while the NO and CEC levels remained higher ( 82.64 ± 20.56 ) μmol/L and ( 5.41 ± 1.29 ) nmol/L in the asthma group; ( 86.12 ± 21.34 ) μmol/L and ( 5.57 ± 1.12 ) n/ 0.9 μl in the MP group] than those in the control group two weeks later (P< 0.05 or 0.01 ). than those in the control group two weeks later (P< 0.05 or 0.01 ). CONCLUSIONS: Both NO and OFR take part in the pathogenesis of asthma and MP pneumonia. NO and LPO appear to be the sensitive indices for asthma and TXB 2 for MP pneumonia. NO could show the extent of tissue repair after injuries.