Chemiluminescence from eukaryotic and prokaryotic cells: reducing potential and oxygen requirements.

Abstract

Abstract— The postphagocytic microbicidal activity of polymorphonuclear leukocytes (PMNL), the effector phagocytes of the acute inflammatory response, is metabolically characterized by increased glucose oxidation via the hexose monophosphate shunt and by increased non‐mitochondrial oxygen consumption. These metabolic alterations result from the phagocytic activation of a membrane‐associated NADPH:O, oxidoreductase. The products of univalent reduction of O2 by this enzyme, O‐2 and H +, may further react to yield potential microbicidal oxidants such as H2O2, OC1‐‐, OH, and 1AgO2. The microbicidal activity of PMNL is associated with the generation of luminescence. This chemiluminescence correlates with the metabolic generation of reducing potential and O2 consumption, and is proposed to originate from the relaxation of the electronically excited products of microbicidal oxidation. The importance of O2 in microbicidal metabolism will be considered, and data demonstrating the O2‐dependence of PMNL‐chemiluminescence are presented. The phenomenon of chemiluminescence from non‐bioluminescent bacteria is also described, and preliminary data from luminescence studies of Streptococcus faecalis are presented. The relationship of light emission to bacterial metabolism and O2 toxicity is considered. Evidence for the bacterial generation of O‐2 is presented, and the role of O‐2 and H2O2 in oxidative reactions productive of electronic excited molecular products is discussed.