Gülden Michael, Mörchel Sabine, Seibert Hasso
Institut für Experimentelle Toxikologie, Universitätsklinikum Kiel, Weimarer Str. 8, Haus 3, Germany.
Toxicol Lett. 2003 Feb 3;137(3):159-68. doi: 10.1016/s0378-4274(02)00399-5.
The aim of the present study was to measure the influence of albumin binding on cytotoxic concentrations of chemicals and to determine binding parameters which can be used for quantitative in vitro-in vivo extrapolations. Protein binding parameters were determined from cytotoxic potencies measured with Balb/c 3T3 cells cultured in the presence of 18 and 600 microM bovine serum albumin (BSA). A subset of 27 chemicals from the Multicenter Evaluation of In Vitro Cytotoxicity (MEIC) project was investigated. At 18 microM BSA the EC(50)-values ranged from 2.54 microM (As(III)) to 527 mM (ethylene glycol). Increasing the BSA concentration either decreased the cytotoxic potency (12 compounds) by factors up to 34 (pentachlorophenol), had no effect (14 compounds), or increased the cytotoxicity (paraquat). Calculated molar ratios of binding ranged from 0.05 (Hg(2+)) to 4.8 moles per mole albumin (acetylic salicylic acid). At 18 microM BSA fractional binding of most of these compounds was low (<25%) but increased up to > or =90% (hexachlorophene, mercuric chloride, thioridazine, pentachlorophenol) at 600 microM BSA. The results obtained in general were compatible with available protein binding data and can be used to calculate equipotent concentrations of chemicals in biological systems containing different albumin concentrations.
本研究的目的是测量白蛋白结合对化学物质细胞毒性浓度的影响，并确定可用于体外-体内定量外推的结合参数。蛋白质结合参数是根据在含有18微摩尔和600微摩尔牛血清白蛋白（BSA）的条件下培养的Balb/c 3T3细胞所测得的细胞毒性效力来确定的。对多中心体外细胞毒性评估（MEIC）项目中的27种化学物质进行了研究。在18微摩尔BSA条件下，半数效应浓度（EC50）值范围从2.54微摩尔（三价砷）到527毫摩尔（乙二醇）。提高BSA浓度，要么使细胞毒性效力降低（12种化合物），降低倍数高达34倍（五氯苯酚），要么没有影响（14种化合物），要么增加细胞毒性（百草枯）。计算得到的结合摩尔比范围从0.05（汞离子）到每摩尔白蛋白4.8摩尔（乙酰水杨酸）。在18微摩尔BSA条件下，这些化合物大多数的结合分数较低（<25%），但在600微摩尔BSA条件下增加到≥90%（六氯酚、氯化汞、硫利达嗪、五氯苯酚）。总体而言，所获得的结果与现有的蛋白质结合数据相符，可用于计算含有不同白蛋白浓度的生物系统中化学物质的等效浓度。
