Photomodulation of oxidative metabolism and electron chain enzymes in rat liver mitochondria

Low-level laser irradiation has been applied in a variety of laboratory studies and clinical trials for photostimulation over the last three decades, Considerable skepticism exists regarding the concept of photostimulation within the medical community, One of the major difficulties with photoirradiation research is that it lacks experimentally supportable mechanisms for the alleged photobiostimulatory effects, This study was undertaken to determine whether oxidative metabolism and electron chain enzymes in rat liver mitochondria can be modulated by photoirradiation, Oxygen consumption, phosphate potential, and energy charge of rat liver mitochondria were determined following photoirradiation, Activities of mitochondrial enzymes were analyzed to assess the specific enzymes that are directly involved,vith the photostimulatory process, An argon-dye laser at a wavelength of 660 nm and at a power density of 10 mW/cm(2)? was used as a photon source, Photoirradiation significantly 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 activities 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 dehydrogenase were not affected by photoirradiation.