Absorption measurements of cell monolayers relevant to mechanisms of laser phototherapy: reduction or oxidation of cytochrome c oxidase under laser radiation at 632.8 nm

Objective: The objective of this work was a further investigation of redox mechanisms of laser phototherapy on the cellular level.

Background data: Cytochrome c oxidase, the terminal enzyme of the mitochondrial respiratory chain, is believed to work as the photoacceptor to modulate cellular metabolism in laser phototherapy.

Materials and methods: The changes in the absorption spectra of HeLa-cell monolayers before and after irradiation at 632.8 nm using fast multi-channel recording were evaluated by the intensity ratio between the peaks at 770 and 670 nm (intensity ratio criterion).