Copper uptake and retention in liver parenchymal cells isolated from nutritionally copper-deficient rats.
Copper uptake and retention were studied in primary cultures of liver parenchymal cells isolated from copper-deficient rats. Male Sprague-Dawley rats were fed a copper-deficient diet (less than 1 mg Cu/kg) for 10 wk. Copper-deficient rats were characterized by low copper concentrations in plasma and liver, anemia, low plasma ceruloplasmin oxidase activity and increased 64Cu whole-body retention. Freshly isolated liver parenchymal cells from copper-deficient rats showed a higher 64Cu influx, which was associated with a higher apparent Vmax of 45 +/- 4 pmol Cu.mg protein-1.min-1 as compared with 30 +/- 3 pmol Cu.mg protein-1.min-1 for cells isolated from copper-sufficient rats. No significant difference in the apparent Km (approximately 30 mumol/L) was observed. Relative 64Cu efflux from cells from copper-deficient rats was significantly smaller than the efflux from cells from copper-sufficient rats after prelabeling as determined by 2-h efflux experiments. Analysis of the medium after efflux from cells from copper-deficient rats showed elevated protein-associated 64Cu, suggesting a higher incorporation of radioactive copper during metalloprotein synthesis. Effects of copper deficiency persist in primary cultures of parenchymal cells derived from copper-deficient rats, and short-term cultures of these cells offer a prospect for the study of cell biological aspects of the metabolic adaptation of the liver to copper deficiency.
Van den Berg
G J
GJ
Interfaculty Reactor Institute, Delft University of Technology, The Netherlands.
de Goeij
J J
JJ
Bock
I
I
Gijbels
M J
MJ
Brouwer
A
A
Lei
K Y
KY
Hendriks
H F
HF
D000818:Animals; D001692:Biological Transport; D002478:Cells, Cultured; D002570:Ceruloplasmin / Q000378:metabolism; D003300:Copper / Q000172:deficiency* / Q000378:metabolism*; D003301:Copper Radioisotopes; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008297:Male; D011485:Protein Binding; D051381:Rats; D011919:Rats, Inbred Strains
D003301:Copper Radioisotopes; D003300:Copper; D002570:Ceruloplasmin