Beckwith-Hall B M, Nicholson J K, Nicholls A W, Foxall P J, Lindon J C, Connor S C, Abdi M, Connelly J, Holmes E
Department of Chemistry, Birkbeck College, University of London, Gordon House, 29 Gordon Square, London WC1H 0PP, U.K.
Chem Res Toxicol. 1998 Apr;11(4):260-72. doi: 10.1021/tx9700679.
1H NMR spectroscopy of urine combined with pattern recognition (PR) methods of data analysis has been used to investigate the time-related biochemical changes induced in Sprague-Dawley rats by three model hepatotoxins: alpha-naphthyl isothiocyanate (ANIT), d-(+)-galactosamine (GalN), and butylated hydroxytoluene (BHT). The development of hepatic lesions was monitored by conventional plasma analysis and liver histopathology. Urine was collected continuously postdosing up to 144 h and analyzed by 600-MHz 1H NMR spectroscopy. NMR spectra of the urine samples showed a number of time-dependent perturbations of endogenous metabolite levels that were characteristic for each hepatotoxin. Biochemical changes common to all three hepatotoxins included a reduction in the urinary excretion of citrate and 2-oxoglutarate and an increased excretion of taurine and creatine. Increased urinary excretion of betaine, urocanic acid, tyrosine, threonine, and glutamate was characteristic of GalN toxicity. Both GalN and ANIT caused increased urinary excretion of bile acids, while glycosuria was evident in BHT- and ANIT-treated rats. Data reduction of the NMR spectra into 256 integrated regions was used to further analyze the data. Mean values of each integrated region were analyzed by principal components analysis (PCA). Each toxin gave a unique time-related metabolic trajectory that could be visualized in two-dimensional PCA maps and in which the maximum distance from the control point corresponded to the time of greatest cellular injury (confirmed by conventional toxicological tests). Thereafter, the metabolic trajectories changed direction and moved back toward the control region of the PR map during the postdose recovery phase. The combination of urinary metabolites which were significantly altered at various time points allowed for differentiation between biliary and parenchymal injury. This NMR-PR approach to the noninvasive detection of liver lesions will be of value in furthering the understanding of hepatotoxic mechanisms and assisting in the discovery of novel biomarkers of hepatotoxicity.
尿的1H核磁共振光谱结合模式识别（PR）数据分析方法，已用于研究三种模型肝毒素对Sprague-Dawley大鼠诱导的与时间相关的生化变化，这三种肝毒素分别是：α-萘基异硫氰酸酯（ANIT）、d-(+)-半乳糖胺（GalN）和丁基化羟基甲苯（BHT）。通过常规血浆分析和肝脏组织病理学监测肝损伤的发展。给药后连续收集尿液达144小时，并通过600兆赫1H核磁共振光谱进行分析。尿液样本的核磁共振光谱显示出许多内源性代谢物水平随时间的扰动，这是每种肝毒素的特征。所有三种肝毒素共有的生化变化包括柠檬酸盐和2-氧代戊二酸的尿排泄减少，以及牛磺酸和肌酸的排泄增加。甜菜碱、尿刊酸、酪氨酸、苏氨酸和谷氨酸的尿排泄增加是GalN毒性的特征。GalN和ANIT均导致胆汁酸的尿排泄增加，而在BHT和ANIT处理的大鼠中出现糖尿。将核磁共振光谱数据简化为256个积分区域用于进一步分析数据。通过主成分分析（PCA）分析每个积分区域的平均值。每种毒素都给出了独特的与时间相关的代谢轨迹，这可以在二维PCA图中可视化，其中距对照点的最大距离对应于最大细胞损伤的时间（通过常规毒理学试验证实）。此后，在给药后恢复阶段，代谢轨迹改变方向并向PR图的对照区域移动。在不同时间点显著改变的尿代谢物组合允许区分胆汁损伤和实质损伤。这种用于肝损伤无创检测的核磁共振-PR方法将有助于进一步理解肝毒性机制，并有助于发现新型肝毒性生物标志物。
