慢性冷暴露对小鼠肝脏抗氧化功能的影响

Effects of Chronic Cold Exposure on Hepatic Antioxidant Function in Mice

本试验旨在探讨慢性冷暴露对小鼠肝脏抗氧化功能的影响。体内慢性冷暴露模型建立:试验将12只3周龄C57BL/6雄性小鼠饲养1周后随机分为2组(对照组和冷暴露组),每组6只。冷暴露组小鼠每日随机放置在4℃环境中3 h,连续4周。冷暴露结束后将所有小鼠同时安乐死,并收集其血液和肝脏。体外冷暴露模型建立:将小鼠肝细胞系AML12细胞随机分为4组(对照组、冷暴露1 h组、冷暴露3 h组、冷暴露6 h组),先在37℃培养箱中培养24 h,然后将冷暴露组细胞置于32℃培养箱中分别亚低温冷刺激0、12、24、36 h,冷刺激结束后将细胞刮取下来进行后续试验。用酶联免疫吸附测定(ELISA)法对小鼠血清中谷胱甘肽(GSH)和丙二醛(MDA)含量进行检测,用Western Blot检测小鼠肝细胞和肝脏组织中抗氧化蛋白硫氧还蛋白-1(Trx-1)和硫氧还蛋白互作蛋白(TXNIP)的表达情况。结果显示:与对照组相比,冷刺激36 h后AML12细胞数量显著下降(P<0.05)。与对照组相比,Trx-1的蛋白表达量在组织和细胞中都显著降低(P<0.05),TXNIP的蛋白表达量显著增加(P<0.05),ELISA检测发现血清GSH含量显著减少(P<0.05),血清MDA含量显著增加(P<0.05)。综上所述,32℃亚低温处理一段时间后会对小鼠肝细胞造成一定的氧化损伤。4℃慢性冷暴露4周后,导致小鼠的抗氧化功能下降。

The purpose of this study was to investigate the effects of chronic cold exposure on the antioxidant function of mouse.Establishment of chronic cold exposure model in vivo:twelve 3-week-old C57BL/6 male mice were randomly divided into two groups(control group and cold exposure group)after feeding for one week,with 6 mice in each group.Mice in the cold exposure group were randomly placed at 4℃for 3 h every day for 4 consecutive weeks.All mice were euthanized at the same time after cold exposure and their blood and liver were collected.In vitro cold exposure model establishment:mice liver cell line AML12 cells were randomly divided into 4 groups(control group,cold exposure group for 1 h,cold exposure group for 3 h,cold exposure group for 6 h).The cells of the cold exposure group were cultured in 37℃incubator for 24 h,and then placed in 32℃incubator for 0,12,24,36 h,respectively.After the cold stimulation,the cells were scraped off for follow-up tests.The serum glutathione(GSH)and malondialdehyde(MDA)contents were detected by enzyme linked immunosorbent assay(ELISA).Western Blot was used to measure the expression of thioredoxin-1(Trx-1)and thioredoxin interacting protein(TXNIP)in mouse liver cells and tissues.The results showed that compared with the control group,the number of AML12 cells was significantly decreased after36 h cold stimulation(P<0.05).Compared with the control group,the protein expression levels of Trx-1 was significantly decreased in both tissues and cells(P<0.05),the protein expression levels of TXNIP was significantly increased(P<0.05).ELISA showed that the content of GSH was significantly decreased(P<0.05)and the content of MDA in serum was significantly increased(P<0.05).In summary,mild low temperature treatment at 32℃for a period of time can cause certain oxidative damage to mouse liver cells.After 4 weeks of chronic cold exposure at 4℃,the antioxidant function of mice decrease.