Subcellular distribution of lead in cultured rat hepatocytes

Journal Article · Mon Oct 01 04:00:00 EDT 1984 · Environ. Res.; (United States)

DOI:https://doi.org/10.1016/0013-9351(84)90126-9· OSTI ID:6017727

Mittelstaedt, R A; Pounds, J G

A clear understanding of the sequence and molecular mechanism of the events involved in lead toxicity is hampered by a lack of information about lead compartmentation within the cell. As part of a continuing effort to identify the mechanism by which lead affects cellular functions, we examined the subcellular distribution of /sup 210/Pb in cultured hepatocytes. The cells were isolated, labeled, homogenized in sucrose-N-((2-hydroxyethyl)piperazine)-N'-2-ethanesulfonic acid buffer, and fractionated into mitochondrial, microsomal, and cytosolic components by differential centrifugation. Complete fractionation of the cells revealed that 71% of the cellular /sup 210/Pb was associated with the mitochondria, 5% with the microsomes, and 24% with the cytosol. A modified, rapid fractionation procedure indicated that 45% of the cellular lead was associated with both the mitochondria and the cytosol and 10% with the microsomes. When the cells were separated into total particulates and cytosol with a single centrifugation, 22% of the /sup 210/Pb was associated with the soluble fraction. The process of homogenization and fractionation of the isolated hepatocytes altered the intracellular distribution of /sup 210/Pb. This experimental approach to studying the localization of lead may be compromised by the redistribution of /sup 210/Pb during the extensive centrifugations and resuspensions required for subcellular fractionation and suggests that the subcellular distribution patterns of /sup 210/Pb obtained by the fractionation of cells reflects the distribution of lead in the homogenate rather than the distribution of /sup 210/Pb in the intact cell.

• Research Organization: National Center for Toxicological Research, Jefferson, AR
• OSTI ID: 6017727
• Journal Information: Environ. Res.; (United States), Journal Name: Environ. Res.; (United States) Vol. 35:1; ISSN ENVRA
• Country of Publication: United States
• Language: English

Related Subjects

560301* -- Chemicals Metabolism & Toxicology-- Cells-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALPHA DECAY RADIOISOTOPES
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL LOCALIZATION
BODY
CELL CULTURES
DATA
DIGESTIVE SYSTEM
ELEMENTS
EVEN-EVEN NUCLEI
EXPERIMENTAL DATA
FRACTIONATION
GLANDS
HEAVY NUCLEI
INFORMATION
ISOTOPE APPLICATIONS
ISOTOPES
LEAD
LEAD 210
LEAD ISOTOPES
LIVER
MAMMALS
METALS
MOLECULAR BIOLOGY
NUCLEI
NUMERICAL DATA
ORGANS
RADIOISOTOPES
RATS
RODENTS
SEPARATION PROCESSES
TOXICITY
TRACER TECHNIQUES
VERTEBRATES
YEARS LIVING RADIOISOTOPES