Oxygen consumption of the isolated carotid body tissue (cat)
- 30 Downloads
The oxygen consumption of the isolated carotid body tissue measured in microchambers (volumes 12 and 20 μl) was 0.0051 μl O2/mg wet weight min for an average of 54 measurements at 22±1°C, if the calculation was based on the oxygen pressure decrease of the surrounding medium measured polarographically in the range from 120 to 50 torr. It is bound to the presence of exogenous substrate and almost completely inhibited by antimycin but not significantly altered by addition of EGTA (4–16 mM) or Ca2+ (2mM).
Measurements performed at higher oxygen pressures (300 to 100 torr) in the medium show that the oxygen consumption of isolated carotid body tissue is independent of oxygen pressure at these high oxygen pressures.
The findings obtained under the above conditions argue in favor of a mitochondrial oxygen consumption. The results are discussed with regard to data obtained with needle electrodes in the perfused organ.
Key wordsCarotid body Polarographic measurement of oxygen consumption Mitochondrial oxygen consumption Antimycin inhibition Oxygen pressure Independent oxygen consumption
Unable to display preview. Download preview PDF.
- 1.Acker, H.: Der lokale Sauerstoffdruck im Glomus caroticum der Katze und seine Bedeutung für die nervöse chemorezeptive Aktivität. Habil.-Schrift, Bochum 1975Google Scholar
- 2.Acker, H., Lübbers, D. W.: The meaning of the tissueP O 2 of the carotid body for the chemoreceptive process. In: The peripheral arterial chemoreceptors (M. J. Purves, ed.), pp. 325–343. Cambridge: Cambridge University Press 1975Google Scholar
- 4.Daly, M., de Burgh, Lambertsen, C. J., Schweitzer, A.: Observations on the volume of blood flow and oxygen utilization of the carotid body in the cat. J. Physiol. (Lond.)125, 67–89 (1954)Google Scholar
- 7.Huxley, H. E.: Electron microscope studies in the structure of natural and synthetic protein filaments from striated muscle. J. molec. Biol.7, 281–308 (1963)Google Scholar
- 9.Purves, M. J.: The effect of hypoxia, hypercapnia and hypotension upon carotid body blood flow and oxygen consumption in the cat. J. Physiol. (Lond.)209, 395–416 (1970)Google Scholar
- 10.Schäfer, D., Schäfer, S., Lübbers, D. W.: On the population of mitochondria in type I glomus cells of the cat and in cells of other organs. Arzneimittel-Forsch. (Drug Res.)23, 1611 (1973)Google Scholar
- 12.Starlinger, H., Lübbers, D. W.: Polarographis measurements of the oxygen pressure performed simultaneously with optical measurements of the redox state of the respiratory chain in suspensions of mitochondria under steady-state conditions at low oxygen tensions. Pflügers Arch.341, 15–22 (1973)PubMedCrossRefGoogle Scholar
- 13.Warburg, O.: Versuche an überlebendem Carcinomgewebe (Methoden). Biochem. Z.142, 317 (1923)Google Scholar