PHOTOMODULATION OF OXIDATIVE-METABOLISM AND ELECTRON CHAIN ENZYMES INRAT-LIVER MITOCHONDRIA

Low-level laser irradiation has been applied in a variety of laborator y studies and clinical trials for photostimulation over the last three decades, Considerable skepticism exists regarding the concept of phot ostimulation within the medical community, One of the major difficulti es with photoirradiation research is that it lacks experimentally supp ortable mechanisms for the alleged photobiostimulatory effects, This s tudy was undertaken to determine whether oxidative metabolism and elec tron chain enzymes in rat liver mitochondria can be modulated by photo irradiation, Oxygen consumption, phosphate potential, and energy charg e of rat liver mitochondria were determined following photoirradiation , Activities of mitochondrial enzymes were analyzed to assess the spec ific enzymes that are directly involved,vith the photostimulatory proc ess, An argon-dye laser at a wavelength of 660 nm and at a power densi ty of 10 mW/cm(2)? was used as a photon source, Photoirradiation signi ficantly increased oxygen consumption (0.6 J/cm(2) and 1.2 J/cm(2), P < 0.05), phosphate potential, and the energy charge (1.8 J/cm(2) and 2 .4 J/cm(2), P < 0.05) of fat liver mitochondria and enhanced the activ ities of NADH: ubiquinone oxidoreductase, ubiquinol :ferricytochrome C oxidoreductase and ferrocytochrome C:oxygen oxidoreductase (0.6 J/cm( 2), 1.2 J/cm(2), 2.4 J/cm(2) and 48 J/cm(2), P < 0.05), The activities of succinate ubiquinone oxidoreductase, ATPase, and lactate dehydroge nase were not affected by photoirradiation.