一氧化氮自由基在鸡氟中毒机理中的作用

Functions of Nitric Oxide in the Mechanism of Chick Fluorosis

为探讨氟对鸡体内一氧化氮 ( NO)代谢和超氧化物歧化酶 ( SOD)活性的影响 ,选用 2 50只 1日龄蛋鸡 ,随机均分为 5组 ,饲喂相同的全价日粮。第 组为正常对照组 ,第 、 、 、 组在日粮中添加不同水平的氟化钠 ,使日粮中氟的含量分别为 50 0、1 0 0 0、1 50 0、2 0 0 0 mg/kg,试验期为 1 50 d。每隔 30 d采集血样 ,测定血清中氟和 NO的含量以及 SOD活性。结果 ,饲料中加氟量与血清中氟含量呈明显的剂量—效应关系 ;氟中毒组鸡血清中 NO含量均高于对照组 ,血清中氟含量与 NO含量间呈显著的正相关 ( r=0 .7394 ,P<0 .0 0 1 ) ,与血清中 SOD活性呈显著的负相关 ( r=-0 .4 56 5,P<0 .0 5) ;可见 ,慢性氟中毒不但刺激机体产生过多的 NO自由基 ,明显地影响 NO的代谢 ,而且抑制 SOD活性。因此 。

To investigate the effects of fluoride on NO metabolism and superoxide dismutase(SOD) activity in chicks,250 one day chicks were randomly divided into 5 groups,50 for each.Group Ⅰ was the control,and other four groups,groupⅡ,Ⅲ,Ⅳ,Ⅴ were fed with the diets containing 500, 1 000 , 1 500 , 2 000 mg/kg of fluorine as sodium fluoride,respectively,for 150 days.The contents of serum fluorine,NO and the activity of SOD were determined at every other 30 days.The results showed as follows:Serum F concentration presented a dose effect regular rule;There were a significantly positive correlation between the content of serum F and that of serum NO( r = 0.734 9 ,P< 0.001 ),and a significantly negative correlation between the content of serum F and activity of serum SOD( r =- 0.456 5 ,P<0.05).Ingesting excessive fluoride increased the NO concentration in serum and decreased the activity of SOD scavenging superoxygen anion free radical(O · 2),and led to the accumulation of NO and O · 2 in body.In conclusion,fluoride has a great influence on the metabolism of NO free radical in chicks,which may be helpful to clarify the mechanism of fluorosis by free radical theory.