水砷暴露大鼠肝损伤和肝纤维化模型的建立

Model establishment of liver injury and fibrosis in rats exposed to oral arsenic solution

目的:建立水砷暴露致大鼠肝损伤及肝纤维化的动物模型,为砷中毒致肝损伤及肝纤维化的机制研究和防治提供较好的实验平台.方法:80只大鼠被随机分成正常对照组和模型组,对照组给予普通饲料和自来水,模型组给予普通饲料和砷水(100mg/L).分别于第1、2、3、4月末各随机处死10只,检测血清样本中谷丙转氨酶(ALT),谷草转氨酶(AST)的含量;取部分肝组织处理后于光镜和电镜观察,了解肝组织病理改变;并应用图像分析法进行Masson染色纤维化面积半定量分析.结果:砷暴露1mo,大鼠肝组织HE染色可见细胞水样变性、脂肪变性及气球样变性,汇管区见炎症细胞浸润,部分肝细胞坏死,但肝小叶结构尚完整.砷暴露3、4mo后大鼠肝组织损伤明显加重,并可见汇管区纤维组织增生,纤维条索形成,肝纤维化趋势明显.电镜下可见砷暴露组大鼠肝脏组织细胞核形状改变,核膜扩张并且不完整,线粒体肿胀,边界不清,极消失.砷暴露大鼠血清ALT、AST的结果比正常对照组增高,ALT在3、4mo后增高更明显(69.36±15.70U/L,104.49±16.86U/Lvs50.68±4.31U/L,均P<0.05).模型组纤维化面积明显增大,造模2、3、4mo后肝组织纤维化面积与正常对照组比较差异有统计学意义(0.48±0.15,0.57±0.11,1.07±0.22vs0.21±0.13,均P<0.05);造模4mo后肝组织纤维化面积与造模1、2、3mo后比较差异也有统计学意义(P<0.05).结论:成功建立了水砷暴露致肝损伤、肝纤维化的动物模型,为砷暴露致肝损伤、肝纤维化的研究提供了较理想的模型.

AIM： To establish a liver injury and fibrosis model in oral arsenic solution exposed rats and to provide a comparatively ideal animal research model for mechanism-study, prevention and cure of liver injury and fibrosis induced by oral arsenic solution exposure. METHODS： Eighty rats were divided into con- trol group and model group at random. Rats in control group were fed with common animal feeds and tap water while model group were fed with common animal feeds and 100 mg/L iAs^3＋ water. Ten rats were executed in each group after 1, 2, 3 and 4 months＇ arsenic-exposure for detection of liver function. Hepatic tissues were observed with optical microscope and transmis- sion electron microscope in order to find out the pathological changes. Masson dyeing was also performed in order to run semi-quantitative analysis with image analysis system. RESULTS： After 1 month＇s arsenic-exposure, hydropic, fatty and ballooning degeneration cells in hepatic lobule, hyperplastic inflamma- tory cells and some necrotic cells in portal area were observed, but the hepatic lobule remained intact. After 3 and 4 months＇ arsenic-exposure, the pathological injury became more and more of rats＇ hepatic tissue severe, fibrous tissues were hyperplastic and trabs were growing in portal area which showed the tendency of liver fibrosis. With transmission electron microscope, shape-change of the cell nucleus, expansion of nuclear membrane and tumid mitochondrion whose pole was disappearing and border blurry was observed. The serum ALT and AST were higher in model group than in control group, the serum ALT had statistical significance between 3, 4 months＇ model groups and control group （69.36 ± 15.70 U/L, 104.49 ± 16.86 U/L vs 50.68 ± 4.31 U/L, both P 〈 0.05）. The size of fibrosis was sig- nificantly increased in model group. There was statistical significance in 2, 3, 4 months＇ model groups compared with control group （0.48 ± 0.15, 0.57 ± 0.11, 1.07 ± 0.22 vs 0.21 ± 0.13, both P 〈 0.05） and so it was in 1, 2, 3 months＇ model groups compared with 4 months＇ model group （P 〈 0.05）. CONCLUSION： The liver injury and fibrosis model in oral arsenic solution exposed rats were successfully established which provides a com- paratively ideal animal research model for the research of arsenic liver injury and fibrosis.