Effects of albumin and histidine on kinetics of copper transport by fibroblasts

Journal Article · Wed Aug 01 04:00:00 EDT 1990 · American Journal of Physiology; (USA)

OSTI ID:6788353

Waldrop, G L; Ettinger, M J ^[1]

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1. State Univ. of New York, Buffalo (USA)

The kinetics of copper transport by fibroblasts were examined and compared with earlier data with hepatocytes to determine the basis of rapid, preferential copper uptake by the liver. The Km and maximal velocity (Vmax) parameters for copper transport by fibroblasts in serum-free media were comparable to the parameters with hepatocytes. As with hepatocytes, albumin markedly inhibited initial rates of copper transport by fibroblasts. Although the only effect of histidine on copper transport by hepatocytes in serum-free media is a small increase in Km, histidine as His2Cu decreases the Vmax of copper transport fivefold with fibroblasts. Moreover, although histidine increases copper accumulation by hepatocytes when transport is inhibited by albumin, histidine further inhibits copper accumulation by fibroblasts when albumin is in the medium. Thus the inhibitory effects of histidine and albumin on copper transport by fibroblasts are additive. The data are consistent with an intermediary role for the His2Cu complex in copper transport. Copper is transported from His2Cu as the free ion, and copper transport is strictly passive with both cell types. The data suggest that rapid uptake by the liver is in part due to the ability of hepatocytes to transport copper from His2Cu more rapidly than other cell types.

• OSTI ID: 6788353
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 259:2 Pt 1; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALBUMINS
AMINO ACIDS
ANIMAL CELLS
AZOLES
BIOLOGICAL EFFECTS
CARBOXYLIC ACIDS
COMPARATIVE EVALUATIONS
CONNECTIVE TISSUE CELLS
COPPER
ELEMENTS
FIBROBLASTS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HISTIDINE
IMIDAZOLES
LIVER CELLS
MEMBRANE TRANSPORT
METABOLISM
METALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PROTEINS
SOMATIC CELLS
TRANSITION ELEMENTS