Balancing of energy‐consuming processes of rat hepatocytes

A method for the quantification of energy consuming processes described by Siems et al.6 for reticulocytes and by Müller et al.10 for ascites tumour cells was applied to balance the ATP‐consumption of isolated rat hepatocytes. On the basis of decreased coupled respiration rates following the specific inhibition of energy‐requiring reactions, the energy demands of protein turnover, nucleic acid synthesis, Na+/K+‐ATPase and Ca2+‐transport of hepatocytes in different incubation media were assessed. These processes together with urea synthesis account for about 60 per cent of the total energy consumption in a glucose and amino acid‐enriched Eagle/Borsook medium. The metabolic flux rates of total ATP‐consumption and ATP‐consumption of single energy‐requiring processes in hepatocytes are compared with those in reticulocytes and different tumour cell types.