Biomaterial Database

Multipoint kinetic method for simultaneously measuring the combined concentrations of acetoacetate-beta-hydroxybutyrate and lactate-pyruvate. 1989

N F Nuwayhid, and G F Johnson, and R D Feld

Department of Pathology, College of Medicine, University of Iowa, Iowa City 52242.

This is a multipoint kinetic method for simultaneously determining acetoacetate (AcAc) plus beta-hydroxybutyrate and lactate plus pyruvate in a single cuvette of the Multistat III centrifugal analyzer. In the first step, AcAc and pyruvate are completely reduced, using 3-hydroxybutyrate dehydrogenase (EC 1.1.1.30) and lactate dehydrogenase (EC 1.1.1.27) in the presence of excess NADH at pH 7.5, to beta-hydroxybutyrate and lactate, respectively. After dilution, the endogenous beta-hydroxybutyrate and lactate and that resulting from reduction are simultaneously oxidized by their respective dehydrogenases in the presence of excess NAD+ at pH 9.0. Adjustment of the relative enzyme concentrations allows simultaneous estimation of AcAc plus beta-hydroxybutyrate and lactate plus pyruvate by analyzing multipoint absorbance data, collected during the oxidation reaction, with use of a two-component linear-regression model. Total run-to-run CVs were 6.4% and 6.1% at 5 mmol/L beta-hydroxybutyrate and 5 mmol/L lactate, respectively. The method was designed to be useful for identifying the cause of an increased anion gap in serum.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D007773	Lactates	Salts or esters of LACTIC ACID containing the general formula CH3CHOHCOOR.
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D011773	Pyruvates	Derivatives of PYRUVIC ACID, including its salts and esters.
D002498	Centrifugation	Process of using a rotating machine to generate centrifugal force to separate substances of different densities, remove moisture, or simulate gravitational effects. It employs a large motor-driven apparatus with a long arm, at the end of which human and animal subjects, biological specimens, or equipment can be revolved and rotated at various speeds to study gravitational effects. (From Websters, 10th ed; McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006885	Hydroxybutyrates	Salts and esters of hydroxybutyric acid.	Hydroxybutyric Acid Derivatives,Hydroxybutyric Acids,Acid Derivatives, Hydroxybutyric
D000090	Acetoacetates	Salts and derivatives of acetoacetic acid.
D000136	Acid-Base Equilibrium	The balance between acids and bases in the BODY FLUIDS. The pH (HYDROGEN-ION CONCENTRATION) of the arterial BLOOD provides an index for the total body acid-base balance.	Anion Gap,Acid-Base Balance,Acid Base Balance,Acid Base Equilibrium,Anion Gaps,Balance, Acid-Base,Equilibrium, Acid-Base,Gap, Anion,Gaps, Anion
D000138	Acidosis	A pathologic condition of acid accumulation or depletion of base in the body. The two main types are RESPIRATORY ACIDOSIS and metabolic acidosis, due to metabolic acid build up.	Metabolic Acidosis,Acidoses,Acidoses, Metabolic,Acidosis, Metabolic,Metabolic Acidoses