title: Detritiation of L-[3-3H]alanine in the glutamate-pyruvate transaminase reaction.
abstract: The detritiation of L-[3-3H]alanine in the reaction catalyzed by pig heart glutamate-pyruvate transaminase was monitored in the absence or presence of lactate dehydrogenase. The results indicated that each monodirectional conversion of L-[3-3H]alanine to [3-3H]pyruvate resulted in the generation of 3HOH at a rate representing one-third of the total 3H flux. No isotopic discrimination in reaction velocity between tritiated and 14C-labelled L-alanine was observed. The mathematical modelling of the reaction revealed that, as a consequence of the detritiation process, the steady-state ratio in L-[3-3H]alanine/[3-3H]pyruvate does not inform on either the absolute or relative size of the amino acid and 2-keto acid pools.
authors.affiliation: Laboratory of Experimental Medicine, Brussels Free University, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Manuel y Keenoy
authors.forename: H
authors.initials: H
authors.lastname: Bodur
authors.forename: W J
authors.initials: WJ
authors.lastname: Malaisse
mesh_terms: D000409:Alanine / Q000378:metabolism*; D000410:Alanine Transaminase / Q000378:metabolism*; D000818:Animals; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008962:Models, Theoretical; D009206:Myocardium / Q000201:enzymology; D013552:Swine; D014316:Tritium / Q000378:metabolism*
chemical_list: D014316:Tritium; D007770:L-Lactate Dehydrogenase; D000410:Alanine Transaminase; D000409:Alanine