The Respiratory Quotients of Normal and Leukemic Mouse Lymphoid Tissue

Abstract

The purpose of this report is to present observations on the effects of glucose on the respiratory rates and quotients of normal lymph nodes and those of mice inoculated with transmission lines of lymphatic leukemia. If, according to Dickens and Simer, the distinguishing metabolic characteristics of tumor tissue are its low respiratory quotient and high glycolytic rates (2), then the high respiratory quotient and high glycolytic rates of leukemic tissue of mice with spontaneous lymphatic leukemia (8) may be due to a mixture of normal and malignant lymphoid cells. Other lines of evidence also suggest this possible explanation of the metabolic traits of leukemic tissue in spontaneous lymphatic leukemia. Glucose depresses the respiratory rate of spontaneous leukemia tissues (8) but not of Jensen sarcoma (3). Cytologically the infiltrated tissues in spontaneous lymphatic leukemia show more variability in the degree of differentiation of cell forms than those of mice inoculated with transmission lines of lymphatic leukemia (6, 8). Cells of spontaneous cases with small nuclei, presumably more mature cells, are associated with greater changes in the respiratory quotient produced by glucose (8). The glycolytic rates of infiltrated tissues of mice inoculated with transmission lines are higher than those in spontaneous cases (8, 9). The conclusions of Dickens and Simer (2) regarding tumor metabolism were based on observations of various normal tissues with cell types quite different from those of the tumors studied. A comparison of normal and malignant tissues of similar cell type would be more enlightening. Normal lymph nodes contrasted with those of mice inoculated with transmission lines of lymphatic leukemia should indicate the differences between normal and malignant lymphoid tissue with respect to the oxidation of glucose. As already mentioned, individual transmission lines of lymphatic leukemia produce infiltrations of a more uniform cell type than those of spontaneous lymphatic leukemia. If leukemia cells show distinct metabolic differences from normal, the metabolic traits of tissues of spontaneous lymphatic leukemia, in which there is a suggestion of a mixture of normal and malignant cells, may be better understood.