Balancing of energy‐consuming processes of rat hepatocytes

Abstract

A method for the quantification of energy consuming processes described by Siems et al. for reticulocytes and by Müller et al. 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.

Evaluation of purine nucleotide loss, lipid peroxidation and ultrastructural alterations in post‐hypoxic hepatocytes.

“…During normoxia the coupled oxygen consumption of cells remained constant throughout the 3 h of the experiment (Table 1). The absolute value of about 3 mmol oxygen min-' (1 cells)-' is in the range of those found for Eagle's basal medium (Schneider et al 1990). …”

“…The coupled oxygen consumption reflected the ATP production (via the mitochondrial respiratory chain), which was determined by the ATP consumption of the cell. One of the dominant ATP consuming processes is protein synthesis (Schneider et al 1990). Taking into account the decreased post-hypoxic oxygen consumption, the share of oxygen uptake required for energy production for protein syntheses was also decreased and recovered only slowly (Fig.…”

“…The loss of ATP, and in connection with that, the loss of ATP-dependent cell functions as a causal component and the increased formation of oxygen-derived free radicals during the post-ischaemic phase seem to be accepted. (Schneider et al 1990). …”

Growth and metabolism of marine fish Chinook salmon embryo cells: response to lack of glucose and glutamine

“…Energy charge (EC) in most mammalian cells is strongly maintained at 0.9 (Schneider et al 1990), and ATP contents were weakly affected by selective inhibition of nutrient uptake, glucose concentration or its depletion, and the addition of hormones or vitamins (Carvalhal et al 2002, Chapman et al 1971). The energy requirements of anabolism and the energy generation of catabolism should be in equilibrium with each other (Vriezen & van Dijken 1998).…”

“…Research on the contribution of glucose and glutamine to energy was always a hot spot (Schneider et al 1990). However, the contribution of other amino acids to energy generation was usually overlooked.…”