染矽尘大鼠血浆一氧化氮、一氧化氮合酶的变化

Changes in plasma level of nitric oxide and bioactivity of nitric oxide synthase in the rats exposed to silica dust

目的 探讨染矽尘不同时点大鼠血浆NO (一氧化氮 )、NOS (一氧化氮合酶 )的变化。方法 采用析因分析的研究设计进行实验 ;气管注射染尘方法建立动物模型 ;称量法测定脏器系数 ;硝酸还原酶法测定血浆NO水平 ;NOS催化L Arg法测定血浆NOS活性。结果 在染尘后第 30天时 ,实验组血浆NO水平高于对照组 (P <0 0 5) ,其他时点差异没有显著性 ,但有升高趋势 ;在染尘后第 2 1、 30、 60天时 ,实验组血浆NOS活力显著低于对照组。控制时间因素进行偏相关分析结果显示实验组血浆NO水平和血浆NOS活力为负相关 (r=- 0 367,P =0 0 2 8)。

Objectives To study the changes in plasma level of nitric oxide(NO)and bioactivity of nitric oxide synthase(NOS)in the rats exposed to silica dust.Methods The experiment was designed with factorial analysis.Animal model was established by intratracheal injection of silica dust.Coefficient of organ was measured by the weighing method.Plasma level of NO was determined by nitric acid reductase method.Plasma activity of NOS was determined by NOS catalyzing L Arg method.Data were analyzed with SAS version 6 12 and graph was plotted with Excel 97.Results Plasma level of NO was higher in the exposed group than that in the control one(P<0 05)only on the thirty days after exposure to silica dust,but there was no significant difference between them on the other time periods,with an increasing trend.Twenty first,thirtith and sixtith day after exposure,plasma activity of NOS was significantly lower in the exposed group than that in the control group.Multivariate regression analysis showed that plasma level of NO in the exposed group correlated inversely with activity of NOS(r=-0 367,P=0 028),adjusted for time variables.Conclusions Silica dust could cause increase in plasma level of NO,and decrease in activity of NOS.