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

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

Dynamic Changes in Collagen Type I and Collagen Type

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 alpha-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 alpha-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 withdrawl 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.