Low R B, Leffingwell C M, Bulman C A
Arch Environ Health. 1980 Jul-Aug;35(4):217-23.
A study was made of the effects of kaolinite, an aluminum silicate found in cigarette smoke and in alveolar macrophages of cigarette smokers, on the in vitro function of rabbit alveolar macrophages. Macrophages lavaged by standard procedures were incubated as adherent monolayers in the presence or absence of kaolinite, and amino acid incorporation into protein and transport subsequently measured. In the presence of dialyzed serum, kaolinite slightly inhibited incorporation into protein during the first 2 to 3 hr of incubation, after which incorporation ceased and a large percentage of newly synthesized protein was released (50% effect at approximately 0.5 mg/ml kaolinite). A dual-isotope experiment indicated that any change in the synthesis of protein which may have occurred was not selective for any protein or group of proteins. Kaolinite also stimulated noncompetitive amino acid accumulation after 2 to 3 hr in the presence of serum. The effects of kaolinite were immediate when incubations were conducted in the absence of serum. Control experiments showed all of the effects of the aluminum silicate to be on the cells and not on the incubation medium. These results suggest that kaolinite is cytotoxic and exerts its effects by a mechanism similar to that proposed for magnesium silicates and silica, in which the naked silicate is immediately cytotoxic, but if coated with serum protein must first be uncoated by lysozomal enzymes before destroying the cells.
对高岭石（一种在香烟烟雾以及吸烟者肺泡巨噬细胞中发现的硅酸铝）对兔肺泡巨噬细胞体外功能的影响进行了研究。通过标准程序灌洗得到的巨噬细胞在有或没有高岭石存在的情况下作为贴壁单层细胞进行培养，随后测定氨基酸掺入蛋白质的情况以及转运情况。在存在透析血清的情况下，高岭石在培养的最初2至3小时内轻微抑制氨基酸掺入蛋白质，此后掺入停止，并且大量新合成的蛋白质被释放（在约0.5mg/ml高岭石时50%的效应）。一项双同位素实验表明，可能发生的蛋白质合成的任何变化对任何蛋白质或蛋白质组都没有选择性。在存在血清的情况下，高岭石在2至3小时后还刺激非竞争性氨基酸积累。当在没有血清的情况下进行培养时，高岭石的作用是即时的。对照实验表明，硅酸铝的所有作用都是对细胞而非对培养基产生的。这些结果表明，高岭石具有细胞毒性，其作用机制与硅酸镁和二氧化硅所提出的机制类似，即裸露的硅酸盐具有即时细胞毒性，但如果被血清蛋白包被，则必须首先被溶酶体酶去除包被才能破坏细胞。
