小鼠感染日本血吸虫肝脏损害的动态观察

Dynamic observation on liver damage in mice infected with Schistosoma jaonicum

目的动态观察和探讨小鼠感染日本血吸虫肝脏虫卵肉芽肿病变及纤维化与血清学改变的相关性。方法小鼠经腹部皮肤感染日本血吸虫尾蚴,定期剖杀小鼠,观察肝脏大体变化并测定肝脏系数;HE染色及Masson胶原纤维染色观察肝虫卵肉芽肿面积及纤维化程度;ELISA检测血清谷草转氨酶(AST),谷丙转氨酶(ALT)含量。放免法检测血清透明质酸(HA),层粘连蛋白(LN),Ⅳ型胶原(Ⅳ-C)含量。结果肉眼观察感染后24d肝脏表面开始出现出血点,29d开始出现粟白色肉芽肿;HE染色发现感染后21d肝脏可见灶性炎症,28d始见虫卵,但无肉芽肿反应,29d可见肉芽肿反应并于42d达到高峰;血清ALT/AST在28d明显升高,39d达到高峰,42d开始下降,70d接近正常水平;统计学分析血清转氨酶水平与肉芽肿面积具有相关性。Masson染色表明肝脏纤维化42d开始出现,以后逐渐加重;血清HA、LN随着纤维化的出现而升高,Ⅳ-C水平无明显改变,但统计分析胶原染色面积与血清纤维化指标无相关性。结论肝脏虫卵肉芽肿和纤维化均是导致小鼠血吸虫病肝脏损害的主要原因,血清转氨酶变化与肝脏的肉芽肿病变动态相一致,并呈显著正相关;血清纤维化指标与肝脏早期纤维化病变无相关性。

The urose of this study was to observe the dynamic changes of liver damage in mice infected with Schistosoma jaonicum（S.jaonicum） and investigate the correlation among granulomatous lesions,liver fibrosis and serological indexes.Mice were infected subcutaneously with cercariae of S.jaonicum,and then sacrificed to observe the athological changes of livers and record the liver index regularly.Liver samles were embedded in araffin for routine histological examination.The sizes of egg granuloma and degrees of liver fibrosis were observed dynamically by HE stain and Masson＇s trichrome stain,resectively.The liver-associated AST and ALT levels in individual serum samles were measured in enzymatic assay using a commercial kit.The content of hyaluronic acid（HA）,laminin（LN） and Ⅳ collagen（Ⅳ-C） in serum were detected by radioimmunoassay.It was found that bleeding oints began to emerge on 24d.i.and yellowish-white dots began to emerge on 29d.i.on the surface of livers.HE stain showed that numerous small and mixed inflammatory cell foci aeared on 21d,and eggs without granulomatous reaction could be seen on 28d.Egg granuloma resented on 29d and the size of the granuloma reached maximum on 42d.i.The ALT/AST level in serum elevated obviously on 28d,eaked on 39d,began to decrease on 42d and was closed to normal level on 70d.i..There were ositive correlation between aminotransferase concentration and the size of liver granuloma of infected mice（P〈0.01）.Masson＇s stain demonstrated that liver fibrosis could be seen from 42d.i.and increased gradually.Meanwhile,the levels of serum HA and LN increased with the emergence of fibrosis.Ⅳ-C,however,showed no obvious change along with fibrosis aggravation.But there were no correlation between fibrosis arameters and Masson＇s stain.It is evident that liver granuloma and fibrosis are the rimary causes for liver damage.The serological aminotransferase changes are consistent with the rogress in liver athology.But serum fibrosis indexes could not reresent early liver fibrosis aroriately.