Living without oxygen: Turtle brain as a model of anaerobic metabolism

P. L. Lutz, M. Rosenthal, Thomas Sick

Research output: Contribution to journalArticle

70 Citations (Scopus)

Abstract

During anoxia, degenerative changes occur so rapidly in the mammalian brain that within a few minutes ion homeostasis is lost, energy sources are depleted and recovery becomes questionable. This vulnerability is characteristic of vertebrate brains in general and is likely a consequence of the high energy demand of brain tissues. Studies of these degenerative processes and of brain anaerobic metabolism are hindered by the rapidity of anoxia-induced changes. In order to investigate anaerobic metabolism, and to define the compensatory processes that promote survival during anoxia, an animal model is needed that has a high brain anaerobic capacity. The turtle is ideal in this regard. In studies reported here, mitochondrial reduction/oxidation reactions in turtle brain were monitored by reflection spectrophotometry, tissue oxygen tension by polarography, ion homeostasis by potassium-selective microelectrodes and metabolite concentrations by assay of freeze-trapped brain samples. Differences between rat and turtle brain were found in the relationship between cytochrome oxidase and tissue oxygenation. In addition, in the turtle brain lactate production was initiated before cytochrome oxidase became fully reduced. These findings suggest a relationship between mitochondrial redox status and anaerobiosis. Maintenance of ion homeostasis and ATP levels suggest that the turtle brain compensates for prolonged anoxia by increased glycolysis, depletion of CP stores and decreased ATP consumption. The identification of anoxia-induced compensatory activity in turtle brain models should offer new insights into anaerobic processes and mechanisms for anoxic brain survival in the mammal.

Original languageEnglish
Pages (from-to)411-425
Number of pages15
JournalMolecular Physiology
Volume8
Issue number3
StatePublished - Dec 1 1985

Fingerprint

Anaerobiosis
Turtles
Metabolism
Brain
Oxygen
Homeostasis
Electron Transport Complex IV
Ions
Tissue
Adenosine Triphosphate
Brain models
Polarographic analysis
Polarography
Mammals
Oxygenation
Redox reactions
Microelectrodes
Spectrophotometry
Metabolites
Glycolysis

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Medicine(all)

Cite this

Lutz, P. L., Rosenthal, M., & Sick, T. (1985). Living without oxygen: Turtle brain as a model of anaerobic metabolism. Molecular Physiology, 8(3), 411-425.

Living without oxygen : Turtle brain as a model of anaerobic metabolism. / Lutz, P. L.; Rosenthal, M.; Sick, Thomas.

In: Molecular Physiology, Vol. 8, No. 3, 01.12.1985, p. 411-425.

Research output: Contribution to journalArticle

Lutz, PL, Rosenthal, M & Sick, T 1985, 'Living without oxygen: Turtle brain as a model of anaerobic metabolism', Molecular Physiology, vol. 8, no. 3, pp. 411-425.
Lutz, P. L. ; Rosenthal, M. ; Sick, Thomas. / Living without oxygen : Turtle brain as a model of anaerobic metabolism. In: Molecular Physiology. 1985 ; Vol. 8, No. 3. pp. 411-425.
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