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Renal transport and metabolism of glutamine
Kingston; s.n; Dec. 1981. 127 p. tab.
Tese em Inglês | MedCarib | ID: med-13645
Biblioteca responsável: JM23.1
Localização: JM23.1; U Thesis
ABSTRACT
The experiments described in this thesis were designed to investigate the mechanism of glutamine transport and the effect of acute acidosis on glutamine transport and metabolism in the rat kidney. The experiments done with kidney slices investigated the effect of several amino acids chosen from different structural groups on uptake of glutamine. Proline (an ammino acid) and glycine (at inhibitory concentrations) were found to inhibit ammonia production and glutamine uptake significantly. When a sodium free incubation buffer was used the inhibitory effect of proline and glycine on glutamine uptake disappeared, indicating that the inhibition by proline was sodium dependent. In similar experiments with isolated kidney proximal tubules in a sodium containing buffer, proline also caused a decrease in glutamine uptake and ammonia production. Intracellular/extracellular glutamine distributions ratios in tubules however, showed a marked increase in the presence of proline. The explanation for this is not that proline shares a transport site with glutamine but rather that it is metabolised to glutamate which causes an inhibition of phosphate dependent glutaminase and hence decreased glutamine utilisation. This decreased utilisation leads to an accumulation of glutamine within the renal cell and subsequently increased intracellular/extracellular glutamine distribution ratios. The inhibitory effect of proline on glutamine uptake was much less in experiments with kidney slices from chronically acidotic rats. Isolated tubules from acutely acidotic rats showed increased intracellular/extracellular glutamine distribution ratios, increased ammonia production and glutamine uptake in tubules. When tubules from normal rats were incubated in sera from acutely acidotic rats there was a similar increase in intracellular/extracellular glutamine distribution ratios, ammonia production and glutamine uptake. The effect of the serum however, was not due to the accumulation of glutamate because glutamate levels in tubules were unchanged after incubation in sera from the acutely acidotic rats (AU)
Assuntos
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Coleções: Bases de dados internacionais Base de dados: MedCarib Assunto principal: Glutamina / Rim Limite: Animais Idioma: Inglês Ano de publicação: 1981 Tipo de documento: Tese
Buscar no Google
Coleções: Bases de dados internacionais Base de dados: MedCarib Assunto principal: Glutamina / Rim Limite: Animais Idioma: Inglês Ano de publicação: 1981 Tipo de documento: Tese
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