Recently there has been increasing realisation of tile important part played by citric acid in the body’s metabolism. Thus administration of pyruvic acid, the intermediate metabolite common to the utilisation of carbohydrate, protein and perhaps fat, causes increased urinary excretion of citrate. Many tissues can form citrate by condensation of pyruvate and oxalacetate followed by reduction, an...

We describe an enzymic method for conveniently measuring citrate in serum or urine. Interfering enzyme proteins are removed by a disposable ultrafilter ("Ultrafree"; Worthington Diagnostics), obviating the need for hazardous protein precipitants. A 50 mmol/L Tris buffer adequately controls pH, no lactate dehydrogenase is necessary in the reagents, and the reaction of citrate catalyzed by citrat...

BACKGROUND Hypocitraturia, or low urinary citrate excretion is known as a risk for nephrolithiasis. Though urinary citrate excretion is basically determined by acid-base balance, metabolic acidosis is not always manifest in urinary stone patients with hypocitraturia. From our stone clinic data, we estimated the incidence of hypocitraturia and addressed its causes in the absence of obvious acid-...

Foods that are high in citrate content generally are assumed to deliver alkali load when consumed irrespective of the accompanying cation. The object of this randomized, crossover study was to compare the effects of orange juice with those of lemonade on acid-base profile and urinary stone risks under controlled metabolic conditions. Thirteen volunteers (nine healthy subjects and four stone for...

BACKGROUND/AIMS Our work in a rodent model of urinary calcium suggests genetic and gender effects on increased residual variability in urine chemistries. Based on these findings, we hypothesized that sex would similarly be associated with residual variation in human urine solutes. Sex-related effects on residuals might affect the establishment of physiological baselines and error in medical ass...

Although considerable data have been gathered on the metabolism of the ash constituents, the literature concerning the interrelations between calcium and magnesium metabolism is very limited. This experiment was undertaken to ascertain whether an increased intake of calcium would affect the urinary and fecal excretion of magnesium and eice r’ersn, thus showing intcrrclations between the metabol...