2,4-二氯苯酚诱导鲫鱼肝脏自由基的产生和脂质过氧化

以α-苯基-N-叔丁基甲亚胺-N-氧化物(α-phenyl-N-tert-butylnitrone,PBN)为自旋捕获剂,利用电子顺磁共振(electronparamagnetic resonance,EPR)研究了2,4-二氯苯酚(2,4-dichlorophenol,2,4-DCP)腹腔注射24h后,引起鲫鱼(Carassius auratus)幼体肝脏内自由基含量变化.结果表明,不同剂量2,4-DCP(0.025,0.05,0.5,5,25 mg/kg)腹腔注射24h后可引起鲫鱼肝脏内自由基信号明显增强,与对照组相比具有显著性差异(p＜0.05).自由基的产生与2,4-DCP注射剂量呈较好的剂量-效应关系,回归方程为:y=1189ln(x)+9220,r²=0.9856.EPR波谱的3组双重峰分裂谱线为典型的PBN捕获羟自由基形成PBN/'OH的EPR波谱,经谱图解析表明,PBN捕获自由基形成加合物的超精细分裂常数aN=13.7 Gauss,aH=1.8Gauss,g因子为2.0058.与文献报道的PBN捕获羟自由基的特征参数一致.研究发现,2,4-DCP腹腔注射引起鲫鱼肝脏丙二醛(malondialdehyde,MDA)含量明显增加,与对照组相比有显著性差异(p＜0.05),并对2,4-DCP诱导鲫鱼肝脏自由基的产生与脂质过氧化的机理进行了探讨.

Free Radical Generation and Lipid Peroxidation Induced by 2,4-Dichlorophenol in Liver of Carassius auratus

Free radical generation in liver of larval fish (Carassius auratus) after 2,4-dichlorophenol (2,4-DCP) injected intraperitoneally 24 h was studied with electron paramagnetic resonance (EPR) spin trapping technique and alpha-phenyl-N-tert-butylnitrone (PBN) as spin trap reagent. The results show that there is a significant increase of free radical generation in the liver of the fish treated with 2,4-DCP (0.025, 0.05, 0.5, 5, 25 mg/kg) compared with that of the control (p<0.05). The free radical generation correlates well with the dose of 2,4-DCP administered. The regress equation for dose-effect relation is y = 1189ln(x) + 9220, r2 = 0.9856. The six-line composed of three groups with two hyperfine splitting peaks in each shows a typical PBN/*OH EPR spectrum. The hyperfine splitting constants for the PBN-adducts is alphaN = 13.7 Gauss, alphaH= 1.8 Gauss, g factor is 2.0058, which is consistent with the characteristics of PBN-hydroxyl radical adduct reported from the literature. Results also show that there is a significant increase for malondialdehyde (MDA) content in the treated groups compared with that of the control (p<0.05). The mechanisms of free radical generation and lipid peroxidation induced by 2,4-DCP are discussed in this study.