Proton leakage is the mechanism for hematoporphyrin photosensitization-promoted inactivation of rat liver mitochondria

<正> The effects of hematoporphyrin photosensitization on the energy-transducing functions of isolated rat liver mitochondria have been studied. By using the measurements of the illumination time-and hematoporphyrin concentration-dependent variations of bioenergetical parameters of mitochondria, it is shown clearly that the photosensitization-promoted proton leakage of inner mitochondrial membrane, together with the resultant dissipation of proton electrochemical gradient, is the mechanism leading to the impairment of oxidative phosphorylation of mitochondria.