Abstract
A feedback-controlled oxystat system is described maintaining steady-state O2 partial pressures (pO2) between 0.01 mmHg (14 nM-O2) and 150 mmHg (210 microM-O2) and simultaneously monitoring O2 uptake at rates between 0.1 and 120 microM-O2 X min-1 in suspensions of cells, in subcellular fractions and in solutions of enzymes. At pO2 values between 0.2 and 150 mmHg (0.28 and 210 microM-O2) a polarographic O2 sensor was used, and below a pO2 of 0.2 mmHg (0.28 microM-O2) the O2-dependent luminescence of the photobacterium Vibrio fischeri was utilized to monitor the actual pO2. At a selected pO2, O2 supply is maintained by injecting appropriate amounts of O2-saturated aqueous medium into the reaction chamber by using a motor-driven burette. The oxystat system is under control of a computer that reads the O2 sensors, interacts with the motor-driven burette, calculates the O2 uptake from the amounts of O2-saturated medium added, collects data from further measuring devices and provides the documentation of the results during incubation.
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]
- Fossati P., Prencipe L., Berti G. Use of 3,5-dichloro-2-hydroxybenzenesulfonic acid/4-aminophenazone chromogenic system in direct enzymic assay of uric acid in serum and urine. Clin Chem. 1980 Feb;26(2):227–231. [PubMed] [Google Scholar]
- Garrison J. C., Ford G. D. An improved method for measurement of oxygen consumption at constant oxygen tension. J Appl Physiol. 1970 May;28(5):685–688. doi: 10.1152/jappl.1970.28.5.685. [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]
- 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]
- Lloyd D., James K., Williams J., Williams N. A membrane-covered photobacterium probe for oxygen measurements in the nanomolar range. Anal Biochem. 1981 Sep 1;116(1):17–21. doi: 10.1016/0003-2697(81)90315-8. [DOI] [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]
- de Groot H., Haas W. O2-independent damage of cytochrome P450 by CCl4-metabolites in hepatic microsomes. FEBS Lett. 1980 Jun 30;115(2):253–256. doi: 10.1016/0014-5793(80)81180-x. [DOI] [PubMed] [Google Scholar]