Cystine and dibasic amino acid uptake by opossum kidney cells
- Children's Hospital of Philadelphia, PA (USA)
The characteristics of the uptake of L-cystine by the continuous opossum kidney cell line, OK, were examined. Uptake of cystine is rapid and, in contrast to other continuous cultured cell lines, these cells retain the cystine/dibasic amino acid transport system which is found in vivo and in freshly isolated kidney tissue. Confluent monolayers of cells also fail to show the presence of the cystine/glutamate transport system present in LLC-PK1 cells, fibroblasts, and cultured hepatocytes. Uptake of cystine occurs via a high-affinity saturable process which is independent of medium sodium concentration. The predominant site of cystine transport is across the apical cell membrane. The intracellular concentration of GSH far exceeds that of cystine with a ratio greater than 100:1 for GSH:cysteine. Incubation of cells for 5 minutes with a physiological level of labelled cystine resulted in the labelling of 66% and 5% of the total intracellular cysteine and glutathione, respectively. The ability of these cells to reflect the shared cystine/dibasic amino acid transport system makes them a suitable model for investigation of the cystine carrier which is altered in human cystinuria.
- OSTI ID:
- 6874858
- Journal Information:
- Journal of Cellular Physiology; (USA), Vol. 143:3; ISSN 0021-9541
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
AMINO ACIDS
MEMBRANE TRANSPORT
CYSTINE
CELL CULTURES
CELL MEMBRANES
DOSE-RESPONSE RELATIONSHIPS
KIDNEYS
MARSUPIALS
SULFUR ISOTOPES
TRACER TECHNIQUES
ANIMALS
BODY
CARBOXYLIC ACIDS
CELL CONSTITUENTS
DISULFIDES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MEMBRANES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques