快速老化小鼠P8肝脏组织形态学变化及氧化损伤的研究

摘要

Objective To evaluate the feasibility of liver senescence model with senescence accelerated mouse prone 8 (SAMP8), and to explore the possible mechanism of oxidative stress in the process of liver aging in SAMP8. Methods Male SAMP8 mice at the age of 9 months were chosen as research objects, and senescence accelerated mouse resistance 1 (SAMR1) mice were used for normal control. Histopathological changes in the liver of SAMR1 and SAMP8 mice were observed by hematoxylin-eosin (HE), Sudan Ⅳ and Masson staining. Senescence associated β-galactosidase activity was measured by histoehemical staining method, and the activities of superoxide dismutase (SOD), eatalase (CAT), glutathione peroxidase (GSH-Px) and the level of malondialdehyde (MDA) in liver homogenate were examined by chemical colorimetry. Results Compared with SAMR1 group, the liver degenerative changes of SAMP8 mice were observed by microscopy, such as extensive fatty degeneration, focal necrosis of hepatocytes and inflammatory cells infiltration. Meanwhile, senescence associated β-galactosidase-positive cells were significantly increased in SAMP8 group [(78.1±11.0) vs.( 23.9±8.8),t=10.887, P<0.01]. In addition, the activities of SOD, CAT and GSH-Px in liver homogenate were decreased [SOD: (214.8 ± 34.8) vs. ( 295.3 ± 29.7), t = 4.975,P<0.01;CAT: (23.0±4.0) vs. ( 36.3±8.3),t=4.084,P<0.01;GSH-Px: (524.0±74.2) vs. (648. 4±102.8) ,t=2. 776, P<0. 05]and the level of MDA was markedly increased ((2.3±0.2) vs. (1.8±0. 1),t = 6. 329, P<0. 01]. Conclusions SAMP8 mice is a feasible animal model for the study of liver senescence, and oxidative stress may play an important role in the process of liver aging in SAMP8.%目的 评价快速老化小鼠P8(SAMP8)作为肝脏衰老动物模型的可行性,并探讨氧化应激在SAMP8肝脏衰老过程的作用机制. 方法 选择9月龄雄性SAMP8为研究对象,抗快速老化小鼠R1亚系(SAMRl)为模型对照,采用苏木精-伊红(HE)、苏丹Ⅳ和Masson染色观察两组小鼠肝脏的组织病理学改变,组织化学染色法测定肝脏衰老相关β-半乳糖苷酶活性,化学比色法测定肝组织匀浆中丙二醛(MDA)含量及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)的活性. 结果与SAMR1组比较,SAMP8组肝组织出现肝细胞广泛的脂肪变性、局灶性坏死及炎性细胞浸润等退行性改变,衰老相关β-半乳糖苷酶染色阳性细胞明显增多(SAMP8组为78.1±11.0,SAMR1组为23.9±8.8,t=10.887,P<0.01),SOD、CAT、GSH-Px活力明显降低(SOD:SAMP8组为214.8±34.8,SAMR1组为295.3±29.7,t=4.975,P<0.01;CAT:SAMP8组为23.0±4.0,SAMR1组为36.3±8.3,t=4.084,P<0.01;GSH-Px:SAMP8组为524.0±74.2,SAMR1组为648.4±102.8,t=2.776,P<0.05),MDA含量明显增高(SAMP8组为2.3±0.2,SAMR1组为1.8±0.1,t=6.329,P<0.01). 结论 SAMP8小鼠可作为研究肝脏衰老的动物模型,氧化应激在SAMP8肝脏衰老过程中可能起重要作用.