Cytotoxic Amyloid Peptides Inhibit Cellular 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) Reduction by Enhancing MTT Formazan Exocytosis
Article first published online: 18 NOV 2002
Journal of Neurochemistry
Volume 69, Issue 6, pages 2285–2293, December 1997
How to Cite
Liu, Y. and Schubert, D. (1997), Cytotoxic Amyloid Peptides Inhibit Cellular 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) Reduction by Enhancing MTT Formazan Exocytosis. Journal of Neurochemistry, 69: 2285–2293. doi: 10.1046/j.1471-4159.1997.69062285.x
- Issue published online: 18 NOV 2002
- Article first published online: 18 NOV 2002
- Resubmitted manuscript received July 11, 1997; accepted July 17, 1997.
- Alzheimer's disease;
- Amyloid peptides;
- 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide;
Abstract: Amyloid β peptide (Aβ) neurotoxicity is believed to play a central role in the pathogenesis of Alzheimer's disease. An early indicator of Aβ toxicity is the inhibition of cellular 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction to MTT formazan, a widely used assay for measuring cell viability. In this report we show that Aβ and other cytotoxic amyloid peptides such as human amylin dramatically enhance MTT formazan exocytosis, resulting in the inhibition of cellular MTT reduction. Only the amyloid peptides that are known to be cytotoxic enhanced MTT formazan exocytosis. Basal MTT formazan exocytosis and amyloid peptide-enhanced MTT formazan exocytosis are blocked by several drugs with diverse known effects. These and other data suggest that MTT formazan exocytosis is a multistep process and that cytotoxic amyloid peptides enhance MTT formazan exocytosis through an intracellular signal transduction pathway.