摘要目的 观察不同体重指数大鼠血清中氧化应激指标4-羟基壬烯醛(HNE)、硫氧还蛋白(Trx)及其还原酶(TrxR)浓度及活性对大鼠肺损伤的作用和机制.方法 健康雄性SD大鼠45只,体重200~240 g,按随机数字表法分为正常组、消瘦组和肥胖组,每组15只.造模成功后留取血清、肺组织等标本进行实验.测定血清4-HNE、Trx、TrxR的含量及后两者活性.结果 显微镜下观察大鼠肺组织切片,消瘦组和肥胖组平均内衬间隔(MLI)明显增高(均P<0.01),且消瘦组大鼠MLI(85±9)明显高于肥胖组(77±6,P<0.05).但肥胖组大鼠BALF炎症细胞数明显增高(P<0.01).肥胖组4-HNE水平[(25±9)mg/L]显著高于正常组[(15±5)mg/L,P<0.05)],消瘦组与正常组比较差异无统计学意义(P>0.05);消瘦组TrxR水平[(7.7±1.4)μg/ml]显著高于正常组和肥胖组[(6.2±1.3)μg/ml,(4.9±1.4)μg/ml,均P<0.05)],肥胖组TrxR水平显著低于正常组(P<0.05);三组间Trx水平比较差异无统计学意义(P>0.05).消瘦组Trx活性[(32.4±8.5)×10-3A·min-1·mg-1]明显高于正常组[(19.5±3.3)×10-3A·min-1·mg-1]和肥胖组[(11.3±7.5)×10-3A·min-1·mg-1,均P<0.01],肥胖组Trx活性显著低于正常组(P<0.05);消瘦组TrxR活性[(17.6±4.6)×10-3 A·min-1·mg-1]显著高于肥胖组[(7.8±2.3)×10-3A·min-1·mg-1,P<0.01],而二组与正常组比较差异无统计学意义(P>0.05).结论 体重指数过高或过低均可使氧化/抗氧化失衡,导致机体的氧化应激反应造成大鼠肺组织损伤.

abstractsObjective To investigate the influence of different diets on serum protein expression levels of 4-hydroxynonenal (4-HNE), thioredoxin (Trx), thioredoxin reductase (TrxR) and the activities of Trx and TrxR, and to explore the effect of damage to the lung tissue and the underlying mechanisms of different body mass index caused by different diets in the rat models .Method Healthy clean male SD rats were randomly divided into normal group , emaciation group and fat group , which were raised by different diets for 6 months.Then the rats were sacrificed and the serum and lung tissue were prepared .The levels of 4-HNE,Trx and TrxR in peripheral blood were quantitatively analyzed by enzyme-linked immunosorbent assay(ELISA),and the activities of Trx and TrxR were measured by chemical methods .Results Compared with the normal group , the lung tissue had more apparent emphysema in the emaciation and the fat groups under light microscope , and more inflammatory cell infiltration in alveolar septum was observed in the fat group.The levels of 4-HNE in the fat group [(24.7 ±8.7) mg/L] was significantly higher than that in the normal group[(15.4 ±4.7)mg/L,P<0.05)],but there was no significant difference(P>0.05)in the levels of 4-HNE between the emaciation and the normal groups .The levels of TrxR in the emaciation group [ (7.7 ± 1.4)μg/ml] was significantly higher than that in the normal and the fat groups [(6.2 ±1.1),(4.9 ±1.4)μg/ml,all P<0.05) ] .The level of TrxR in the fat group was significantly lower than that in the normal group (P<0.05); The differences in the levels of Trx among the 3 groups were not significant (P>0.05).The activity of Trx in the emaciation group[(32.4 ±8.5) ×10-3A· min-1· mg-1]was significantly higher than that in the normal group[(19.6 ±3.3) ×10-3A· min-1· mg-1]and the fat group[(11.3 ±7.5) ×10-3A· min-1· mg-1,all P<0.01].The activity of Trx in the fat group was significantly lower than that in the normal group(P<0.05).The activity of TrxR in the emaciation group [(17.6 ±4.6) ×10-3A· min-1· mg-1]was significantly higher than that in the fat group[(7.8 ±2.3) ×10-3A· min-1· mg-1,P<0.01], but the TrxR activity of the 2 groups showed no significant difference as compared with the normal group ( P >0.05 ) . Conclusion Both high BMI and low BMI can affect the oxidative stress of the body , resulting in increased oxidants and decreased antioxidants ,and can cause damage to the lung tissue in the rat models .