Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Northern Campus, Guangzhou, Guangdong, China.
Toxicol In Vitro. 2012 Jun;26(4):636-44. doi: 10.1016/j.tiv.2012.02.006. Epub 2012 Feb 28.
MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] method is one of the most widely used methods to analyze cell proliferation and viability. It is taken up through endocytosis and is reduced by mitochondrial enzymes as well as endosomal/lysosomal compartments, then is transported to cell surfaces to form needle-like MTT formazans; however the effect of MTT itself still remains elusive. Our objective was to investigate the direct effects of MTT on in vitro SH-SY5Y cells. Results showed that the endocytosis of MTT did not cause obvious lesion and induce cell death, but the metabolism and exocytosis of MTT could dramatically damage cells. Our results also indicated that MTT could activate apoptosis related factors such as caspase-8, caspase-3 or accelerate the leakage of cell contents after the appearance of MTT formazan crystals. The present data suggest MTT method should be carefully chosen; otherwise the cell viability would be underestimated and incomparable.
MTT [3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐]法是分析细胞增殖和活力最常用的方法之一。它通过内吞作用被摄取，并被线粒体酶以及内体/溶酶体区室还原，然后被转运到细胞表面形成针状的 MTT 甲臜；然而，MTT 本身的作用仍然难以捉摸。我们的目的是研究 MTT 对体外 SH-SY5Y 细胞的直接影响。结果表明，MTT 的内吞作用不会导致明显的损伤和诱导细胞死亡，但 MTT 的代谢和胞吐作用会严重破坏细胞。我们的结果还表明，MTT 可以激活凋亡相关因子，如 caspase-8、caspase-3，或在 MTT 甲臜晶体出现后加速细胞内容物的渗漏。本数据提示 MTT 法应慎重选择；否则，细胞活力会被低估且无法比较。
