ISSN:
1573-4927
Keywords:
amino acid transport
;
glutathione
;
sheep erythrocyte
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract An inherited amino acid transport deficiency results in low concentrations of glutathione (GSH) in the erythrocytes of certain sheep. Earlier studies based on phenotyping according to GSH concentrations indicated that the gene Tr H, which controls normal levels of GSH, behaves as if dominant or incompletely dominant to the allele Tr h, which controls the GSH deficiency. The present paper shows that when sheep are classified according to amino acid transport activity, the Tr H gene behaves as if codominant to Tr h. Erythrocytes from sheep homozygous for the Tr H gene exhibit rapid saturable l-alanine influx (apparent K m ,21.6mm; V max, 22.4 mmol/liter cells/hr). Cells from sheep homozygous for the Tr h gene exhibit slow nonsaturable l-alanine uptake (0.55 mmol/liter cells/hr at 50mm extracellular l-alanine). Cells from heterozygous sheep show saturable l-alanine uptake with a diminished V max (apparent K m, 19.1mm; V max, 12.7 mmol/liter cells/hr). These erythrocytes have a significantly lower GSH concentration than cells from Tr H, TrH sheep but similar intracellular levels of dibasic amino acids.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00483969
Permalink
