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A Corriat

Publications and source records attributed to A Corriat.

5 recordsLinked to original sources
PubMed1987

L-proline uptake in human fibroblasts: evidence for a high-affinity system in addition to system A.

Proline uptake was studied in human skin fibroblasts by simultaneous running of kinetic and inhibition experiments on the same cell lines. Two systems for proline uptake were shown: a high-affinity system not inhibited by alpha-(methylamino)isobutyric acid and a low affinity system inhibited by this amino acid (i.e. system A). These results appear to be of interest, firstly because up till now, system A was considered preferable for proline uptake in human fibroblasts, and secondly because they illustrate the need for combined inhibition and kinetic studies of amino acid uptake, especially when the substrate concentration range used and the respective Km of the systems do not allow their detection by kinetic analysis alone. Furthermore, this high-affinity system may have major physiological implications.

Aminoisobutyric Acids↗
PubMed1983

Transport of L-histidine by human diploid fibroblasts in culture.

The transport of L-histidine has been characterized in skin derived diploid human fibroblasts, cultured under strictly controlled conditions. The transport measurements were made on cells grown to subconfluency after 60 to 90 min timed preincubation. The data, at substrate concentrations ranging from 0.050 to 10 mmol/l, were analyzed by a computer program. A saturable transport system (Km = 0.25 mmol/l, Vmax = 17 nmol/mg protein per min) and a nonsaturable component of influx (Kd = 1.6 +/- 0.4 nmol/mg protein/min per mmol) were found. L-Histidine displayed no Na+ requirement at either low or high concentrations. Inhibition analysis demonstrated that L-histidine uptake at low concentration was poorly inhibited by amino acids known to be effective inhibitors of system A. The largest fraction of L-histidine uptake was inhibited by 2-amino-bicyclo (2,2,1)-heptane-2-carboxylic acid (BCH), leucine, and tryptophan. These results indicated that L-histidine is transported in human fibroblasts mainly by the Na+ independent system L. The differences between this cell type and others studied previously are discussed.

Amino Acids↗
PubMed1983

Defective galactose oxidation in a patient with glycogen storage disease and Fanconi syndrome.

Carbohydrate metabolism was studied in a child with atypical glycogen storage disease and Fanconi syndrome. Massive glucosuria, partial resistance to glucagon and abnormal responses to carbohydrate loads, mainly in the form of major impairment of galactose utilization were found, as reported in previous cases. Increased blood lactate to pyruvate ratios, observed in a few cases of idiopathic Fanconi syndrome, were not present. [1-14C]Galactose oxidation was normal in erythrocytes, but reduced in fresh minced liver tissue, despite normal activities of hepatic galactokinase, uridyltransferase, and UDP-glucose 4-epimerase in homogenates of frozen liver. These data suggest a defect in hepatic galactose metabolism not so far identified.

Child, Preschool↗