吸烟相关剂量镉致大鼠肝脏氧化损伤的实验研究

发布时间：2018-01-05 12:14

本文关键词：吸烟相关剂量镉致大鼠肝脏氧化损伤的实验研究　出处：《吉林大学》2009年硕士论文　论文类型：学位论文

【摘要】： 【目的】应用Wistar大鼠建立吸烟相关剂量镉动物模型,观察吸烟相关剂量镉对大鼠肝脏结构和功能的影响,并探讨其可能的机制。【方法】建立吸烟相关剂量镉染毒动物模型,分别于染毒第20周、44周处死大鼠,留取血清及肝脏;ICP-MS法检测肝脏镉、锌元素含量;血清AST、ALT含量检测进行肝功能评价;彩色多普勒超声、组织切片观察对肝脏形态学变化进行评价;生化试剂盒检测肝组织MDA、GSH含量及SOD活力;RT-PCR检测肝脏组织Bcl-2基因表达;Western Blot检测肝脏组织MTs表达;免疫组化法检测肝脏组织Bcl-2、MTs的表达。【结果】1)与生理盐水组比,20周染毒组肝脏组织中镉含量显著升高,p0.01。到44周时染毒组肝组织镉含量相对于20周染毒组下降,但仍高于44周生理盐水组,p0.05。2)与生理盐水组相比,20周染毒组血清ALT明显升高,p0.05,44周染毒组血清ALT略升高,但差异无统计学意义。染毒20周及44周组AST与生理盐水组比较,无明显变化。3)染毒20周及44周,肝脏彩色多普勒超声未见明显异常;HE染色组织学观察显示, 20周染毒组及44周染毒组均出现肝细胞体积、核体积增大,肝细胞广泛发生颗粒变性,粗颗粒状的染色质位于核膜周边,在中央静脉、叶间静脉周围有灶状的淋巴细胞浸润,枯否氏细胞肿大,数量增加,并见灶状坏死。4)与生理盐水组相比,20周及44周染毒组肝组织中GSH含量均明显下降(P20W0.05, P44W0.01);肝组织总SOD活力均显著下降(p0.01);MDA含量均显著增高(p0.05)。5)染毒后MT、Bcl-2在蛋白水平的表达均增强;但Bcl-2 mRNA水平的表达与生理盐水组比较,无显著差异。【结论】吸烟相关剂量镉可造成肝脏的氧化损伤,同时启动了机体抗氧化系统,但最终仍不能避免肝功能受损及肝脏组织结构的破坏。该结果提供了低剂量镉对肝脏有损伤的实验依据,对于劝说吸烟人群戒烟及饮食中避免镉摄入有实际意义。
[Abstract]:[objective] to establish a smoking-related dose cadmium animal model in Wistar rats, to observe the effect of smoking related dose cadmium on the liver structure and function of rats, and to explore its possible mechanism. [methods] the animal model of smoking related dose cadmium exposure was established. The rats were killed at the 20th week of exposure to cadmium, and the serum and liver were collected. The contents of cadmium and zinc in liver were detected by ICP-MS. The liver function was evaluated by the determination of alt in serum. The changes of liver morphology were evaluated by color Doppler ultrasound and histological observation. The content of MDA-GSH and the activity of SOD in liver tissue were detected by biochemical kit. RT-PCR was used to detect the expression of Bcl-2 gene in liver tissue. Western Blot was used to detect the expression of MTs in liver tissue. Immunohistochemical method was used to detect the expression of BCL-2 MTs in liver tissue. [results] 1) compared with the saline group, the cadmium content in the liver tissue of the 20 week exposure group was significantly higher than that of the control group (P 0.01). At 44 weeks, the cadmium content of the liver tissue in the exposure group was lower than that in the 20 week group. But it was still higher than that in the saline group at 44 weeks (p0.05.2) compared with the saline group, the serum ALT in the 20 week exposure group was significantly higher than that in the control group, and the serum ALT level in the 44 week group was slightly higher than that in the control group. However, there was no significant difference in AST between the 20 and 44 week groups compared with the saline group. 3) at 20 and 44 weeks of exposure, there was no obvious abnormality in liver color Doppler ultrasound. Histological observation of HE staining showed that hepatocyte volume was increased in 20 week group and 44 week group, and hepatocytes were widely denatured, and coarse granular chromatin was located around the nuclear membrane. In the central vein, there were focal lymphocytic infiltration around the interlobar vein, Kupffer's cells were enlarged and the number of Kupffer cells increased, and focal necrosis. 4) compared with the saline group. In the 20 and 44 week groups, the content of GSH in liver tissue decreased significantly (P 20W 0.05, P 44W 0.01). The activity of total SOD in liver tissue decreased significantly (P 0.01). The expression of MDA Bcl-2 at protein level was significantly increased after exposure to MDA. However, there was no significant difference in the expression of Bcl-2 mRNA between the saline group and the normal saline group. [conclusion] smoking related dose of cadmium can cause oxidative damage to the liver and activate the antioxidant system. However, the damage of liver function and liver tissue structure can not be avoided in the end. This result provides the experimental evidence of liver injury caused by low dose cadmium. It has practical significance for persuading smokers to quit smoking and avoid cadmium intake in diet.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2009
【分类号】：R363;R575

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