Measurement of superoxide release from single pulmonary alveolar macrophages

K. A. DiGregorio, E. V. Cilento, R. C. Lantz

Research output: Contribution to journalArticlepeer-review

26 Scopus citations


An electroptical method was developed to quantify superoxide (O2-) release from single rat pulmonary alveolar macrophages (PAM) during adherence to the bottom of a culture dish. This was done by measuring the reduction of nitro blue tetrazolium (NBT) to a diformazan precipitate at 550 nm from videorecorded images of individual cells. Temporal changes in cell optical density, which are proportional to the mass of diformazan produced, were calculated from video-photometric measurements of the change in light intensity over individual cells. Total diformazan produced increased 78 and 126% with an increase in NBT from 0.5 to 1.0 and 2.0 mg/ml, respectively. Total diformazan produced and maximum rate of production among individual PAM varied two- to threefold providing strong evidence for heterogeneity in O2- production. Specific inhibition of O2- production by superoxide dismutase, iodoacetate, and chlorpromazine significantly reduced the total diformazan produced and maximum rate of diformazan production. Hydrogen peroxide was not involved in NBT reduction, since catalase alone did not significantly change diformazan production. This novel method to quantify O2- release from single PAM should be valuable in analyzing heterogeneity and single cell kinetics of O2- production, in assessing the effects of exposure of cells to particulates on O2- release, and in relating release to electrophysiological measurements.

Original languageEnglish (US)
Pages (from-to)C677-C683
JournalAmerican Journal of Physiology - Cell Physiology
Issue number6 (21/6)
StatePublished - 1987

ASJC Scopus subject areas

  • Physiology
  • Cell Biology


Dive into the research topics of 'Measurement of superoxide release from single pulmonary alveolar macrophages'. Together they form a unique fingerprint.

Cite this