Uncoupling of oxidative phosphorylation in rat liver mitochondria by chloroethanols

Conference · Mon Mar 11 00:00:00 EST 1991 · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)

OSTI ID:5373738

Bhat, H K; Asimakis, G K; Anasari, G A.S. ^[1]

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1. Univ. of Texas Medical Branch, Galveston (United States)

Chloroethanols are toxic chemicals used in the industry and also formed as a result of the metabolism of several widely used halogenated hydrocarbons. The effect of 2-chloroethanol (CE), 2,2-dichloroethanol (DCE) and 2,2,2-trichloroethanol (TCE) on rat liver mitochondrial respiration was studied. Rat liver mitochondria were prepared in a mitochondrial isolation medium consisting of 250 mM sucrose, 10 mM Tris-HCl and 1 mM EDTA. Respiration of the mitochondrial suspension was determined with an oxygen electrode at 25C and the polarographic buffer consisted of 250 mM mannitol, 10 mM KCl, 10 mM K{sub 2}HPO{sub 4}, 5 mM MgCl{sub 2}, 0.2 mM EDTA and 10 mM Tris-HCl. With succinate as the respiratory substrate and using chloroethanols, CE stimulated respiration by 28.2 {plus minus} 6.5% and DCE by 202.7 {plus minus} 8.2% while TCE inhibited mitochondrial respiration. The effect of change in the concentration of chloroethanols on mitochondrial respiration was also studied. CE showed maximum stimulation at 600 mM, DCE at 150 mM and TCE at 30 mM. Respiratory stimulation was independent of mitochondrial protein concentration. Chloroethanols inhibited mitochondrial respiration when glutamate-malate was used as the respiratory substrate. Estimation of adenosine triphosphate (ATP) generation showed that chloroethanols inhibited the synthesis of ATP. These results indicate that chloroethanols stimulate mitochondrial respiration by uncoupling oxidative phosphorylation and that the uncoupling potency is proportional to the extent of chlorination.

• OSTI ID: 5373738
• Report Number(s): CONF-9104107-; CODEN: FAJOE
• Journal Information: FASEB Journal (Federation of American Societies for Experimental Biology); (United States), Vol. 5:4; Conference: 75. annual meeting of the Federation of American Societies for Experimental Biology (FASEB), Atlanta, GA (United States), 21-25 Apr 1991; ISSN 0892-6638
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CHLORINATED AROMATIC HYDROCARBONS
BIOLOGICAL EFFECTS
MITOCHONDRIA
RESPIRATION
ATP
EDTA
INHIBITION
LIVER
METABOLISM
PHOSPHORYLATION
RATS
AMINO ACIDS
ANIMALS
AROMATICS
BODY
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CHELATING AGENTS
CHEMICAL REACTIONS
DIGESTIVE SYSTEM
GLANDS
HALOGENATED AROMATIC HYDROCARBONS
MAMMALS
NUCLEOTIDES
ORGANIC ACIDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANS
RODENTS
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology