Zinc uptake into endothelial cells involves a carrier mediated component

Conference · Fri Mar 15 04:00:00 EST 1991 · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)

OSTI ID:5215221

Bobilya, D J; Briske-Anderson, M; Reeves, P G ^[1]

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1. USDA-ARS Human Nutrition Center, Grand Forks, ND (United States)

The mechanism of zinc (Zn) uptake by endothelial cells was examined. Bovine pulmonary endothelial cells were grown to a confluent monolayer in T-25 flasks with minimum essential medium (MEM) containing 10% fetal bovine serum. Zn uptake was studied by replacing the growth medium with experimental media of MEM, 14% EDTA dialyzed serum, and 250 nCi {sup 65}Zn/mL. The transport mechanism was studied by manipulating the composition of the experimental media and measuring the accumulation of {sup 65}Zn by the cells during a 10 min incubation period at 37C, 90% relative humidity, and 5% CO{sub 2}. The rate of Zn uptake increased as the Zn concentration in the media increased from 1 to 26 {mu}M. The data were described by a rectangular hyperbola with V{sub max} = 27.2 {plus minus} 0.84 pmoles Zn and K{sub m} = 4.1 {plus minus} 0.46 {mu}M Zn. The mechanism was studied further with 6 {mu}M added Zn (ZnCl{sub 2}) in the experimental media. Zn uptake was temperature dependent; the rate was less than 6C than at 24C, which was less than at 33C. The Zn uptake rate was reduced by the metabolic inhibitors iodoacetate, sodium fluoride, and N-ethylmaleimide. Cadmium competitively inhibited Zn uptake; copper and manganese had no effect. Increasing the concentration of albumin tin the media reduced the Zn uptake rate over the range from 0 to 40 {mu}M albumin in the media reduced the Zn uptake rate over the range from 0 to 40 {mu}M albumin, but not at 50 {mu}M albumin, with 10 {mu}M Zn. The addition of Zn binding ligands decreased the Zn uptake rate in the absence of serum, but increased the rate when serum was present. These results demonstrate that Zn uptake into endothelial cells is facilitated by a transporter possessing a recognition site that is saturable and at least partially energy dependent. Additionally, the uptake rate apparently is influenced by the ligand to which Zn is bound in the extracellular fluid.

• OSTI ID: 5215221
• Report Number(s): CONF-9104107--
• Conference Information: Journal Name: FASEB Journal (Federation of American Societies for Experimental Biology); (United States) Journal Volume: 5:5
• 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 TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BODY
CADMIUM
CARBOXYLIC ACIDS
CATTLE
CHELATING AGENTS
COPPER
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
EDTA
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
ENDOTHELIUM
EVEN-ODD NUCLEI
INHIBITION
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
LUNGS
MAMMALS
MANGANESE
MEMBRANE TRANSPORT
METABOLISM
METALS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOISOTOPES
RESPIRATORY SYSTEM
RUMINANTS
TEMPERATURE DEPENDENCE
TISSUES
TRACER TECHNIQUES
TRANSITION ELEMENTS
UPTAKE
VERTEBRATES
ZINC
ZINC 65
ZINC ISOTOPES