Studies on the mechanism of metabolic stimulation in polymorphonuclear leucocytes during phagocytosis I. Evidence for superoxide anion involvement in the oxidation of NADPH2

P. Patriarca, P. Dri, K. Kakinuma, F. Tedesco, F. Rossi

Research output: Contribution to journalArticle


1. 1. The oxidation of NADPH2 by leucocyte granules, as measured at acid pH in the presence of Mn2+, was found to be inhibited by superoxide dismutase. 2. 2. Omission of Mn2+ markedly lowered the oxidase activity at acid pH, which was still inhibited by superoxide dismutase. 3. 3. At alkaline pH the oxidase activity was lower than at acid pH, Mn2+ had no stimulatory effect and superoxide dismutase was less inhibitory than at acid pH. 4. 4. During oxidation of NADPH2 by leucocyte granules, reduction of cytochrome c occurred which was partially inhibited by superoxide dismutase. 5. 5. It was concluded that NADPH2 oxidation occurs through an enzymatic reaction and a nonenzymatic chain reaction. Superoxide anion (O2 - and NADPH· free radical would be involved in the chain reaction. The differential sensitivity of NADPH2 oxidation to superoxide dismutase in different experimental conditions (see above 1, 2 and 3) was explained on the basis of changes in the properties of the chain reaction.

Original languageEnglish
Pages (from-to)380-386
Number of pages7
JournalBBA - General Subjects
Issue number2
Publication statusPublished - Apr 7 1975


ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology
  • Medicine(all)

Cite this