Influence of L-3′,5,3-Triiodothyronine on the Oxidative Phosphorylation of Tumour Mitochondria

THE tumour cell differs from the normal cell mainly in its strong unco-ordinated growth. As any form of growth is combined with an increased consumption of energy, the tumour cell must consequently possess an increased energy metabolism compared with that of the normal cell. This increased expenditure of energy of the malignant cell cannot be completely explained by substrate oxidation via the tricarboxylic acid cycle, as the respiration of the tumour cell is no greater than that of the normal cell. According to Warburg 1 the respiration of tumour cells is even less than that of corresponding normal cells. As is well known, glycolysis, that is, the reduction of carbohydrates to lactic acid, which takes place also under aerobic conditions, is considered as a source of the additional energy production.