13C NMR study of hepatic pyruvate carboxylase activity in tumor rats
| Autor: | Lloyd M. Nyhus, Katherine J.M. Liu, Robert A. Kleps, Thomas O. Henderson |
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| Rok vydání: | 1991 |
| Předmět: |
Pyruvate decarboxylation
medicine.medical_specialty Magnetic Resonance Spectroscopy Pyruvate dehydrogenase kinase Citric Acid Cycle Biophysics Pyruvate dehydrogenase phosphatase Biology Models Biological Biochemistry Reference Values Internal medicine medicine Animals Molecular Biology Pyruvate Carboxylase Carbon Isotopes Alanine Mammary Neoplasms Experimental Cell Biology Pyruvate dehydrogenase complex Rats Inbred F344 Rats Pyruvate carboxylase Citric acid cycle Endocrinology Liver Gluconeogenesis Pyruvate carboxylase activity Female |
| Zdroj: | Biochemical and Biophysical Research Communications. 179:366-371 |
| ISSN: | 0006-291X |
| Popis: | Alanine and lactate, as major gluconeogenic substrates, must be converted into oxaloacetate by way of pyruvate carboxylase before their entry into gluconeogenesis. Although it is well known that hepatic gluconeogenesis from these substrates is increased in tumor hosts, the involvement of pyruvate carboxylase has not been demonstrated. In the present study, we examined pyruvate carboxylase activity in the perfused livers of tumor rats using 13C NMR spectroscopy with [3-13C]-alanine as the gluconeogenic substrate. A substantial increase in hepatic [3-13C]-aspartate production was found in the tumor rats. Since aspartate accumulation directly reflects fluxes of alanine through pyruvate carboxylase, the observed increase in hepatic production of [3-13C]-aspartate in tumor rats indicates that pyruvate carboxylase activity is significantly enhanced. |
| Databáze: | OpenAIRE |
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