Regular Article
Diphenyleneiodonium, an NAD(P)H Oxidase Inhibitor, also Potently Inhibits Mitochondrial Reactive Oxygen Species Production,☆☆

https://doi.org/10.1006/bbrc.1998.9729Get rights and content
Under a Creative Commons license
open archive

Abstract

Diphenyleneiodonium (DPI) has frequently been used to inhibit reactive oxygen species (ROS) production mediated by flavoenzymes, particularly NAD(P)H oxidase. This study was undertaken to examine if DPI could also inhibit production of superoxide and H2O2by mitochondria, the major source of cellular ROS. Detection of mitochondrial superoxide by lucigenin-derived chemiluminescence (CL) with unstimulated monocytes/macrophages showed that DPI at concentrations that inhibit NAD(P)H oxidase markedly diminished the production of superoxide by mitochondrial respiration. Similarly, the extracellular H2O2derived from mitochondrial respiration as detected by luminol-derived CL in the presence of horseradish peroxidase was also greatly reduced by DPI. DPI was as potent as rotenone in inhibiting the production of superoxide and H2O2by mitochondrial respiration. With substrate-supported isolated mitochondria, DPI was shown to reduce mitochondrial superoxide production probably through inhibiting NADH–ubiquinone oxidoreductase (complex I).

Keywords

diphenyleneiodonium
NAD(P)H oxidase
mitochondria
superoxide
reactive oxygen species
chemiluminescence

Cited by (0)

Abbreviations used: DPI, diphenyleneiodonium, ROS, reactive oxygen species; TPA, 12-O-tetradecanoyl-13-acetate; CL, chemiluminescence; SOD, superoxide dismutase; PBS, phosphate-buffered saline; FBS, fetal bovine serum

☆☆

Thomas, C. E.Kalyanaraman, B.

1

To whom correspondence should be addressed at Room 7032, Department of Environmental Health Sciences, Johns Hopkins School of Hygiene and Public Health, 615 N. Wolfe Street, Baltimore, MD 21205. Fax: 410-955-0116. E-mail:[email protected].