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Adenosine, Inosine, and Guanosine Protect Glial Cells During Glucose Deprivation and Mitochondrial Inhibition: Correlation Between Protection and ATP Preservation
- Source :
- Journal of Neurochemistry. 71:535-548
- Publication Year :
- 2002
- Publisher :
- Wiley, 2002.
-
Abstract
- The purpose of this study was to determine the mechanism by which adenosine, inosine, and guanosine delay cell death in glial cells (ROC-1) that are subjected to glucose deprivation and mitochondrial respiratory chain inhibition with amobarbital (GDMI). ROC-1 cells are hybrid cells formed by fusion of a rat oligodendrocyte and a rat C6 glioma cell. Under GDMI, ATP was depleted rapidly from ROC-1 cells, followed on a much larger time scale by a loss of cell viability. Restoration of ATP synthesis during this interlude between ATP depletion and cell death prevented further loss of viability. Moreover, the addition of adenosine, inosine, or guanosine immediately before the amobarbital retarded the decline in ATP and preserved cell viability. The protective effects on ATP and viability were dependent on nucleoside concentration between 50 and 1,500 microM. Furthermore, protection required nucleoside transport into the cell and the continued presence of nucleoside during GDMI. A significant positive correlation between ATP content at 16 min and cell viability at 350 min after the onset of GDMI was established (r = 0.98). Modest increases in cellular lactate levels were observed during GDMI (1.2 nmol/mg/min lactate produced); however, incubation with 1,500 microM inosine or guanosine increased lactate accumulation sixfold. The protective effects of inosine and guanosine on cell viability and ATP were >90% blocked after treatment with 50 microM BCX-34, a nucleoside phosphorylase inhibitor. Accordingly, lactate levels also were lower in BCX-34-treated cells incubated with inosine or guanosine. We conclude that under GDMI, the ribose moiety of inosine and guanosine is converted to phosphorylated glycolytic intermediates via the pentose phosphate pathway, and its subsequent catabolism in glycolysis provides the ATP necessary for maintaining plasmalemmal integrity.
- Subjects :
- Adenosine
Cell Survival
Guanosine
Purine nucleoside phosphorylase
Hybrid Cells
Biology
Biochemistry
Electron Transport
Cellular and Molecular Neuroscience
chemistry.chemical_compound
Adenosine Triphosphate
Inosine Monophosphate
Ischemia
medicine
Animals
Glycolysis
Anaerobiosis
Lactic Acid
Pentosyltransferases
Viability assay
Enzyme Inhibitors
GABA Modulators
Inosine
Dose-Response Relationship, Drug
ATP synthase
Adenine Nucleotides
Coformycin
Glioma
Purine Nucleosides
Cell Hypoxia
Guanine Nucleotides
Mitochondria
Rats
Oligodendroglia
Glucose
Neuroprotective Agents
Mitochondrial respiratory chain
chemistry
Astrocytes
biology.protein
Amobarbital
Nucleoside
medicine.drug
Subjects
Details
- ISSN :
- 14714159 and 00223042
- Volume :
- 71
- Database :
- OpenAIRE
- Journal :
- Journal of Neurochemistry
- Accession number :
- edsair.doi.dedup.....1948d53c7ab5296215c0bc9f8e992432