日本血吸虫感染兔Ⅰ型和Ⅲ型胶原动态变化及干扰素-γ对其的作用

Dynamic Changes in Collagen Type Ⅰ and Collagen Type Ⅲ in Rabbits Infected with Schistosoma japonicum and the Effect of Gamma Interferon *

目的 观察感染日本血吸虫的新西兰兔肝脏Ⅰ型和Ⅲ型胶原的动态变化以及γ 干扰素 (IFN γ)对Ⅰ型和Ⅲ型胶原的降解作用。方法 日本血吸虫感染兔在感染后不同时期取 8只病兔肝脏 ,作常规石蜡切片 ,分别进行免疫组织化学α SMA染色、伊红染色和天狼红染色 ,并在偏光显微镜下观察Ⅰ型和Ⅲ型胶原分布情况 ,计算机图像分析计算胶原含量。感染 16wk后 ,给予吡喹酮治疗 ,IFN γ治疗 8wk ,停药观察 4wk。观察IFN γ对Ⅰ型和Ⅲ型胶原沉积的降解作用。结果 感染日本血吸虫的病兔Ⅰ型胶原在第 8周时占总面积百分比的 5 73± 3 40 ,至第2 8周时达总面积百分比的 40 14± 17 0 0 ,约增加了 7倍 ;Ⅲ型胶原则由第 8周时总面积百分比的 1 15± 1 34增加到6 80± 5 19。α SMA阳性细胞表达数则由 2 8± 1 0增加至 7 3± 1 5。自血吸虫感染 16wk开始采用IFN γ治疗 ,8wk后 ,IFN γ治疗组的Ⅰ型和Ⅲ型胶原所占面积百分比分别由原来的 18 5 1± 7 5 2和 4 63± 3 64下降为 2 4wk时的3 0 9± 1 5 4和 0 40± 0 37(P <0 0 1) ,模型对照组和吡喹酮治疗组比较差异具有显著性 (P <0 0 1)。停药 4wk后IFN γ治疗组的Ⅰ型和Ⅲ型胶原所占面积百分比均有所回升 (P <0 0 5 )。结论 IFN γ对日本血吸虫感染的新西兰兔肝纤?

Objective To observe the dynamic changes in collagen type Ⅰ and collagen type Ⅲ in rabbits with schistosomiasis japonica and the treatment effect of gamma interferon on the degradation of collagens in schistosomal hepatic fibrosis.Methods Each rabbit was infected with 80±1 S japonicum cercariae. Liver operations were done at different time points after infection and the liver specimens were embedded with paraffin and stained with α SMA, HE and picric acid Sirius red. The stained slides were observed under polarizing microscope and different collagen areas calculated by computer imagine analysis system. At the 16th week after infection, the infected rabbits received a single dose of praziquantel and gamma interferon for 8 weeks.Results The area percent of collagen type Ⅰ at the 28th week after infection (40 14±17 00) increased about seven fold compared with the 8th week group (5 73±3 40). The area percent of collagen type Ⅲ at the 28th week after infection (6 80±5 19) increased about six fold compared with the 8th week group (1 15±1 34). The α SMA positive cells also increased significantly. After gamma interferon treatment, the area percent of collagen type Ⅰ and type Ⅲ decreased significantly, from 18 51±7 52 and 4 63±3 64 (before treatment) to 3 09±1 54 and 0 40±0 37 (0 and 4 weeks after treatment) ( P <0 01). However, after the withdrawal of gamma interferon treatment,the collagen degradation was reversible.Conclusion Gamma interferon is effective in the treatment of hepatic fibrosis in rabbits infected with S japonicum ,the effect being reversible.