Abstract
By using a new rapid high pressure filtration technique, mitochondrial and cytosolic ATP and ADP contents were determined in isolated hepatocytes at different oxygen partial pressures. At 670 mmHg, subcellular adenine nucleotide contents and ATP/ADP ratios were comparable with values obtained with the digitonin fractionation technique. However at lower oxygen partial pressure ADP appears to be rephosphorylated during digitonin fractionation whereas with high pressure filtration fractionation rephosphorylation of ADP is avoided due to shorter fractionation times. Cytosolic and mitochondrial ATP/ADP ratios decrease if oxygen partial pressure is lowered. However the absolute values of ATP/ADP ratios depend critically on the incubation conditions. Thus incubation of hepatocytes in an oxystat system, where oxygen partial pressure is maintained constant by infusing oxygen-saturated medium and the hepatocyte suspension is continuously stirred, yields much higher subcellular and overall ATP/ADP ratios than incubation in Erlenmeyer flasks gassed with different gas mixtures and shaken in a water bath. This is ascribed to limited diffusion of oxygen from the medium into the cell if the suspension is not mixed thoroughly by stirring. The strong dependence of subcellular ATP/ADP ratios on incubation conditions indicates that oxygen may be one rate-controlling factor for oxidative phosphorylation in the intact cell.
Full text
PDF




Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Berry M. N., Friend D. S. High-yield preparation of isolated rat liver parenchymal cells: a biochemical and fine structural study. J Cell Biol. 1969 Dec;43(3):506–520. doi: 10.1083/jcb.43.3.506. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bienfait H. F., Jacobs J. M., Slater E. C. Mitochondrial oxygen affinity as a function of redox and phosphate potentials. Biochim Biophys Acta. 1975 Mar 20;376(3):446–457. doi: 10.1016/0005-2728(75)90166-8. [DOI] [PubMed] [Google Scholar]
- Chance B., Sies H., Boveris A. Hydroperoxide metabolism in mammalian organs. Physiol Rev. 1979 Jul;59(3):527–605. doi: 10.1152/physrev.1979.59.3.527. [DOI] [PubMed] [Google Scholar]
- Groen A. K., Wanders R. J., Westerhoff H. V., van der Meer R., Tager J. M. Quantification of the contribution of various steps to the control of mitochondrial respiration. J Biol Chem. 1982 Mar 25;257(6):2754–2757. [PubMed] [Google Scholar]
- Heldt H. W., Klingenberg M. Differences between the reactivity of endogenous and exogenous adenine nucleotides in mitochondria as studied at low temperature. Eur J Biochem. 1968 Mar;4(1):1–8. doi: 10.1111/j.1432-1033.1968.tb00165.x. [DOI] [PubMed] [Google Scholar]
- Ji S., Lemasters J. J., Thurman R. G. A non-invasive method to study metabolic events within sublobular regions of hemoglobin-free perfused liver. FEBS Lett. 1980 Apr 21;113(1):37–42. doi: 10.1016/0014-5793(80)80489-3. [DOI] [PubMed] [Google Scholar]
- Jones D. P., Mason H. S. Gradients of O2 concentration in hepatocytes. J Biol Chem. 1978 Jul 25;253(14):4874–4880. [PubMed] [Google Scholar]
- Kacser H., Burns J. A. The control of flux. Symp Soc Exp Biol. 1973;27:65–104. [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Lilley R. M., Stitt M., Mader G., Heldt H. W. Rapid fractionation of wheat leaf protoplasts using membrane filtration : the determination of metabolite levels in the chloroplasts, cytosol, and mitochondria. Plant Physiol. 1982 Oct;70(4):965–970. doi: 10.1104/pp.70.4.965. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Noll T., de Groot H., Wissemann P. A computer-supported oxystat system maintaining steady-state O2 partial pressures and simultaneously monitoring O2 uptake in biological systems. Biochem J. 1986 Jun 15;236(3):765–769. doi: 10.1042/bj2360765. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SCHOLANDER P. F. Oxygen transport through hemoglobin solutions. Science. 1960 Feb 26;131(3400):585–590. doi: 10.1126/science.131.3400.585. [DOI] [PubMed] [Google Scholar]
- Schwenke W. D., Soboll S., Seitz H. J., Sies H. Mitochondrial and cytosolic ATP/ADP ratios in rat liver in vivo. Biochem J. 1981 Nov 15;200(2):405–408. doi: 10.1042/bj2000405. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sies H., Akerboom T. P., Tager J. M. Mitochondrial and cytosolic NADPH systems and isocitrate dehydrogenase indicator metabolites during ureogensis from ammonia in isolated rat hepatocytes. Eur J Biochem. 1977 Jan;72(2):301–307. doi: 10.1111/j.1432-1033.1977.tb11253.x. [DOI] [PubMed] [Google Scholar]
- Sies H. Oxygen gradients during hypoxic steady states in liver. Urate oxidase and cytochrome oxidase as intracellular O2 indicators. Hoppe Seylers Z Physiol Chem. 1977 Aug;358(8):1021–1032. doi: 10.1515/bchm2.1977.358.2.1021. [DOI] [PubMed] [Google Scholar]
- Soboll S., Scholz R., Heldt H. W. Subcellular metabolite concentrations. Dependence of mitochondrial and cytosolic ATP systems on the metabolic state of perfused rat liver. Eur J Biochem. 1978 Jun 15;87(2):377–390. doi: 10.1111/j.1432-1033.1978.tb12387.x. [DOI] [PubMed] [Google Scholar]
- Soboll S., Seitz H. J., Sies H., Ziegler B., Scholz R. Effect of long-chain fatty acyl-CoA on mitochondrial and cytosolic ATP/ADP ratios in the intact liver cell. Biochem J. 1984 Jun 1;220(2):371–376. doi: 10.1042/bj2200371. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zuurendonk P. F., Tischler M. E., Akerboom T. P., Van Der Meer R., Williamson J. R., Tager J. M. Rapid separation of particulate and soluble fractions from isolated cell preparations (digitonin and cell cavitation procedures). Methods Enzymol. 1979;56:207–223. doi: 10.1016/0076-6879(79)56023-6. [DOI] [PubMed] [Google Scholar]
- de Groot H., Noll T. Oxygen gradients: the problem of hypoxia. Biochem Soc Trans. 1987 Jun;15(3):363–365. doi: 10.1042/bst0150363. [DOI] [PubMed] [Google Scholar]
- de Groot H., Noll T., Sies H. Oxygen dependence and subcellular partitioning of hepatic menadione-mediated oxygen uptake. Studies with isolated hepatocytes, mitochondria, and microsomes from rat liver in an oxystat system. Arch Biochem Biophys. 1985 Dec;243(2):556–562. doi: 10.1016/0003-9861(85)90532-6. [DOI] [PubMed] [Google Scholar]
