Semiautomated enzymic microassay for plasma L-alanine.
Plasma L-alanine is deaminated by bacterial alanine-dehydrogenase; the resulting ammonia is dialyzed out and measured by use of a continuous flow phenol-hypochlorite colorimetric microassay. Concentrations in the range of 10-1,000 mumol alanine/l can be determined in a 50-microliter sample. The optimal conditions for the assay are specified. Study of the analytical qualities of the technique shows high specificity, good reproducibility , and a detection limit of 6 mumol/l. Usual values in human plasma from arterial or venous blood are respectively 296 +/- 166 and 376 +/- 214 mumol alanine/l (x +/- 2 SD). The usual values in rats are close to those found in man.
D000409:Alanine / Q000097:blood*; D000594:Amino Acid Oxidoreductases / Q000378:metabolism; D000641:Ammonia / Q000032:analysis; D000818:Animals; D005215:Fasting; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008832:Microchemistry / Q000379:methods; D009243:NAD / Q000378:metabolism; D051381:Rats
D009243:NAD; D000641:Ammonia; D000594:Amino Acid Oxidoreductases; D000409:Alanine