感染犬弓首线虫SD大鼠血清IL-6和IL-8含量的变化

Study on variable IL-6 and IL-8 levels in the serum of SD rats infected with Toxocara canis

目的通过检测白细胞介素-6(IL-6)、白细胞介素-8(IL-8)的含量,在免疫分子水平上探讨大鼠感染犬弓首线虫后免疫功能的变化。方法将80只大鼠随机分为两组,每组40只,实验组每只大鼠灌胃犬弓首线虫感染期虫卵约3 000个(对照组大鼠灌胃生理盐水)。分别于大鼠感染犬弓首线虫后第1、2、3、4、5周随机取实验组和对照组大鼠各8只,常规股动脉取血,分离血清,用放射免疫法测定IL-6、IL-8含量。结果①实验组IL-6含量在第1、2、3、4、5周均高于对照组(P<0.05或P<0.01),第2周达最高值,之后下降;②实验组IL-8含量在第1、2、3、5周高于对照组(P<0.05或P<0.01),第4周与对照组比较差异无统计学意义(P>0.05)。结论 SD大鼠感染犬弓首线虫后血清IL-6含量升高,提示IL-6与抗虫作用有关,但随着时间的推移,这种保护作用逐渐减弱;感染鼠血清趋化性细胞因子IL-8含量升高,且观察期内含量变化不大,提示非特异性免疫功能增强,且在移行期非特异性免疫功能无显著变化。

Objective To investigate the changes in immune function of SD rats infected with Toxocara canis by testing for levels of interleukin-6（IL-6） and interleukin-8（IL-8）.Methods In this study,80 SD rats were randomly divided into two groups（40 SD rats per group）.Each rat in the observation group was infected with 3 000 infective eggs of T.canis while rats in the control group were administered isochoric isotonic Na chloride（2 ml）.Eight rats were randomly selected from both the observation group and the control group in the 1st,2nd,3rd,4th,and 5th week.Blood was collected from the femoral artery and the serum was separated,and then the levels of IL-6 and IL-8 were measured using a radioimmunoassay.Results ①The serum level of IL-6 in the observation group was higher than in the control group in the 1st,2nd,3rd,4th,and 5th week after infection（P0.05 or P0.01）.The serum level of IL-6 in the observation group peaked in the 2nd week and then began to decline.②The serum level of IL-8 in the observation group was higher than in the control group in the 1st,2nd,3rd,and 5th week after infection（P0.05 or P0.01）;the level differed in the 4th week after infection but not significantly（P0.05）.Conclusion In SD rats infected with T.canis,the serum level of IL-6 in an observation group was higher in each stage than the level in a control group,suggesting that IL-6 is related to counteracting the parasite in question but that this protection gradually weakened.The serum level of IL-8 in the observation group was higher in each stage than the level in a control group and changed little during the period of observation.This suggests that the non-specific immunologic function of the host was heightened whereas non-specific immunity did not change markedly in the migratory stage after infection.