Barile F A, Arjun S, Hopkinson D
Department of Natural Sciences, City University of New York at York College, Jamaica, NY 11451, USA.
Toxicol In Vitro. 1993 Mar;7(2):111-6. doi: 10.1016/0887-2333(93)90120-t.
This study was designed to determine the potential of an in vitro model for predicting acute human chemical toxicity. Rat lung epithelial cells (L2) were tested for their ability to incorporate radiolabelled amino acids into newly synthesized proteins, in the absence or presence of increasing doses of the test chemical, during a 24-hr incubation. The MTT assay was also performed as a parallel measure of toxicity. IC(10), IC(50) and IC(75) values (10%, 50% and 75% inhibitory concentrations, respectively) were extrapolated from dose-response curves after linear regression analysis. The biological significance of the results of testing 30 chemicals shows that the experimental IC(50) values were more accurate predictors of human toxicity than equivalent toxic blood concentrations derived from rodent LD(50)s. Overall, the 24-hr protein synthesis experiments were at least as sensitive as the MTT protocol for detecting cytotoxicity. Individually, the toxicity of eight of 15 chemicals was underestimated with the MTT assay. In addition to calculating the correlation coefficient, the hypothesis test for B = 0 (zero slope) was computed for each experiment. This test, which is based on the slope of the sample regression equation, is used to determine the statistical significance of dose-response curves, yet it has not been routinely incorporated into cytotoxicity testing studies. It is anticipated that this procedure, together with a related battery of tests, may supplement or replace currently used animal protocols for human risk assessment.
本研究旨在确定一种体外模型预测人类急性化学毒性的潜力。在24小时的孵育过程中，检测大鼠肺上皮细胞（L2）在不存在或存在递增剂量测试化学品的情况下，将放射性标记氨基酸掺入新合成蛋白质中的能力。还进行了MTT试验作为毒性的平行测量。通过线性回归分析后从剂量-反应曲线外推IC(10)、IC(50)和IC(75)值（分别为10%、50%和75%抑制浓度）。对30种化学品进行测试的结果的生物学意义表明，实验性IC(50)值比从啮齿动物LD(50)得出的等效毒性血药浓度更准确地预测人类毒性。总体而言，24小时蛋白质合成实验在检测细胞毒性方面至少与MTT实验一样敏感。单独来看，15种化学品中有8种的毒性通过MTT试验被低估。除了计算相关系数外，还针对每个实验计算了B = 0（零斜率）的假设检验。该检验基于样本回归方程的斜率，用于确定剂量-反应曲线的统计学意义，但尚未常规纳入细胞毒性测试研究中。预计该程序以及一系列相关测试可能会补充或取代目前用于人类风险评估的动物实验方案。
