儿童铅负荷对血清中SOD、NO、NSE的影响

Effects of Lead Load on Serum SOD,NO and NSE of Childhood

目的 观察不同血铅水平对儿童血清超氧化物歧化酶（SOD）、一氧化氮（NO）和神经元特异性烯醇化酶（NSE）的影响,并探讨其影响机制。方法 选择健康儿童50人（男26人,女24人）,用无火焰石墨炉原子吸收光谱法测定血铅浓度,根据血铅含量分为正常组、低铅组和高铅组。同时测定血清中SOD活力、NO含量和NSE浓度。结果 血铅含量,正常组（血铅〈0.483μmol/L）18人,占36%,低铅组（血铅0.483-0.965μmol/L）20人,占40%,高铅组（血铅〉0.965μmol/L）12人,占24%。随着血铅浓度的升高,SOD活力呈下降趋势,并有显著负相关（r=-0.53,t=4.35,P〈0.01）。低铅组儿童血清NO含量低于正常组,但差异无统计学意义（P〉0.05）;而高铅组则明显低于正常组（P〈0.01）。儿童血清NO含量与血铅浓度呈显著负相关（r=-0.42,t=3.24,P〈0.01）。随着血铅浓度的升高,NSE浓度呈上升趋势,两者呈显著正相关（r=0.53,t=4.37,P〈0.01）。结论 血铅升高时体内SOD活力、NO含量下降,而血清NSE浓度随着升高,这可能是铅诱发机体损伤的作用机制。血清中SOD活力和NO含量下降及NSE浓度的升高可作为临床上判断儿童期早期铅损伤的重要指标。

Objective To observe effects of lead load on serum SOD, NO and NSE of childhood, and to probe into its mechanism. Methods 50 healthy children（26 boys and 24 girls）were divided into 3 groups： normal group, low Pb group and high Pb group. Blood lead levels were measured with flameless AAS. The activity of SOD, the contents of NO and NSE in serum were also detected. Results Blood lead levels in the normal group, the lower group and higher group were 〈 0.483 μmol/L, 0.483 - 0.965 μmol/L and 〉0.965μmol/L respectively for 18（36%）, 20（40%）and 12（24%）children. The activity of SOD decreased with the increase of blood lead level, and correlated negatively with the blood lead level in children（r=- 0.53, t=4.35, P〈0.01）. The content of NO in low Pb group was lower than that of normal group but the difference was not statistically significant（P〈0.05） ; however, in high Pb group the content was significantly lower than that of the normal group（P〈0. 01）. The content of NO in serum of children correlated negatively with the blood lead level（r=-0.42, t=3.24, P（0.01）. As the blood lead levels increasing, the contents of NSE showed increasing trend, demonstrating significant positive correlation（r = 0.53, t = 4.37, P〈0. 01 ）. Conclusions As the blood lead levels increasing, the activity of SOD in body and NO content decreased accompanied with the elevation of NSE content, which might be the reaction mechanism of the adverse effects induced by lead on body. The lowering of the activity of SOD and content of NO, and elevation of NSE in serum might be taken as important indicators of clinical criteria in determining early adverse effects of lead in children.