Abstract: | It was shown that during glutamate+malate oxidation in the presence of creatine, antitumour anthracycline antibiotics strongly inhibit the rate of oxygen uptake by rat heart mitochondria; ADP excess activated the respiration up to the initial level, i.e., that observed after the first addition of ADP. Carboxyatractyloside addition to a system containing creatine (or hexokinase+glucose) results in the stimulation of rubomycin-induced mitochondrial respiration. Substitution of carboxyatractyloside by oligomycin gives very similar results. It is supposed that anthracycline antibiotics exert a manyfold effect on heart mitochondrial membranes which results in impaired compartmentation of enzymatic systems providing for oxidative phosphorylation. |