title: Pyruvate utilization of rabbit reticulocytes--a compartmental study.
abstract: The utilization of [2-14C] pyruvate via the citric acid cycle of rabbit reticulocytes was studied to elucidate the importance of carboxylation- and decarboxylation reactions in this cell type. Unknown flux rates were determined by fitting the observed time-dependent labeling of CO2, alanine, glutamate and aspartate (all carbon atoms and C alpha) to the corresponding set of differential equations. The results reveal a high activity of the shuttle rate between mitochondrial pyruvate and the C4 pool catalysed by the pyruvate carboxylase (v = 19.1 nM/ml cells/min) and the malic enzyme (v = 57.5 mM/ml cells/min) which is comparable with the flux rate within the citrate cycle (v2 = 46.2 nM/ml cells/min). Moreover, our studies provide strong indications for the existence of a pyruvate utilizing metabolic pathway which has not been described so far.
authors.affiliation: Institut für Biochemie, Humboldt-Universität Berlin.
authors.forename: H G
authors.initials: HG
authors.lastname: Holzhütter
authors.forename: M
authors.initials: M
authors.lastname: Müller
authors.forename: R
authors.initials: R
authors.lastname: Dumdey
authors.forename: J
authors.initials: J
authors.lastname: Rathmann
mesh_terms: D000409:Alanine / Q000378:metabolism; D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism; D002451:Cell Compartmentation; D002952:Citric Acid Cycle; D003653:Decarboxylation; D005973:Glutamine / Q000378:metabolism; D007700:Kinetics; D008928:Mitochondria / Q000378:metabolism; D011773:Pyruvates / Q000378:metabolism*; D019289:Pyruvic Acid; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism*
chemical_list: D011773:Pyruvates; D005973:Glutamine; D001224:Aspartic Acid; D019289:Pyruvic Acid; D000409:Alanine