Respiration and glycolysis in the human diploid cell strain WI-38

Assessment of the respiratory and glycolytic capacity of non-growing WI-38 cells shows that, in the absence and presence of added glucose, the mean rates of oxygen consumption were 247 (QO₂ = 5.61) and 208 (QO₂ = 4.73) mμmoles/mg dry wt/hr., respectively. Mean glucose consumption was 225 mμmoles/mg dry wt/ hr. With uniformly labeled ¹⁴C glucose as substrate, 36 mμg atoms of carbon dioxide were produced, corresponding to 15–20% of the total cellular respiration. Mean values for lactate production in the presence and absence of glucose were 345 (Q_L^O2 = 7.85) and 196 (Q_L^O2 = 4.45) mμmoles/mg dry wt/hr., respectively. Human diploid cells in culture age, in the sense that their ability to proliferate decreases with time during serial subcultivation. Studies of their respiratory and glycolytic capacity as a function of the aging process showed that total respiration, glucose respiration and glycolytic capacity were relatively constant for cells in the middle and late passages and indicate that aging in this sense is not directly related to the respiratory and glycolytic capacity of the cell.