Increase in <--H+/e- ratio of the cytochrome c oxidase reaction in mitochondria irradiated with helium-neon laser.

In order to gain a degree of insight into the mitochondrial component/s responsible of the mitochondria-red light interaction, isolated rat liver mitochondria were irradiated with a Helium-Neon laser (energy dose 2 Joules/cm2, light power 10 mW) and measurements made of the activity of cytochrome c oxidase. A low, but statistically significant increase in the oxygen uptake was found, as polarographically measured, in the presence of rotenone and antimycin A, with ascorbate and TMPD used as substrate pair. Measurements were also made both of the electron transfer and of proton pumping activity: as a result of a major stimulation in the proton pumping activity, about 55% increase of <--H+/e- ratio was found in irradiated mitochondria.