Macromolecular weight specificity in covalent binding of bromobenzene

Journal Article · Thu Nov 01 04:00:00 EST 1984 · Toxicol. Appl. Pharmacol.; (United States)

DOI:https://doi.org/10.1016/0041-008X(84)90005-X· OSTI ID:5762461

Sun, J D; Dent, J G

Bromobenzene is a hepatotoxicant that causes centrilobular necrosis. Pretreatment of animals with 3-methylcholanthrene decreases and phenobarbital pretreatment enhances the hepatotoxic action of this compound. We have investigated the macromolecular weight specificity of the covalent interactions of bromobenzene with liver macromolecules following incubation of (/sup 14/C)bromobenzene in isolated hepatocytes. Hepatocytes were prepared from Fischer-344 rats treated for 3 days with 3-methylcholanthrene, phenobarbital, or normal saline. After a 1-hr incubation, total covalent binding, as measured by sodium dodecyl sulfate-equilibrium dialysis, was twofold less in hepatocytes from 3-methylcholanthrene-treated rats and sixfold greater in hepatocytes from phenobarbital-treated rats, as compared to hepatocytes from control animals. Analysis of the arylated macromolecules by electrophoresis on 15% sodium dodecyl sulfate-polyacrylamide disc gels indicated that in the first 1 to 3 min of incubation substantial amounts of covalently bound radiolabel were associated with macromolecules of between 20,000 and 40,000. The amount of radioactivity associated with these macromolecules rapidly diminished in hepatocytes from control and 3-methylcholanthrene-treated animals. In hepatocytes from phenobarbital-treated animals, the amount of radioactivity associated with macromolecules, 20,000, increased throughout the incubation. The amount of radiolabel associated with macromolecules, 20,000, increased in all incubations. When nontoxic doses of phenylmethylsulfonyl fluoride, a specific inhibitor of serine proteases, were added to control hepatocytes incubated with (/sup 14/C)-bromobenzene, the decrease in radioactivity associated with larger (greater than 20,000) macromolecules was inhibited and a corresponding lack of increase in radioactivity associated with smaller macromolecules was observed.

• Research Organization: Chemical Industry Inst. of Toxicology, Research Triangle Park, NC
• OSTI ID: 5762461
• Journal Information: Toxicol. Appl. Pharmacol.; (United States), Journal Name: Toxicol. Appl. Pharmacol.; (United States) Vol. 76:2; ISSN TXAPA
• Country of Publication: United States
• Language: English

Related Subjects

3-METHYLCHOLANTHRENE
550201 -- Biochemistry-- Tracer Techniques
560305* -- Chemicals Metabolism & Toxicology-- Vertebrates-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANESTHETICS
ANIMAL CELLS
ANIMALS
ANTICONVULSANTS
AROMATICS
AZINES
BARBITURATES
BENZENE
BODY
BROMINE COMPOUNDS
CARBON 14 COMPOUNDS
CENTRAL NERVOUS SYSTEM DEPRESSANTS
CHEMICAL BONDS
COMPARATIVE EVALUATIONS
COVALENCE
DIGESTIVE SYSTEM
DRUGS
ENZYME INHIBITORS
ENZYMES
GLANDS
HALOGEN COMPOUNDS
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
HYDROLASES
HYPNOTICS AND SEDATIVES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIVER
LIVER CELLS
MAMMALS
MOLECULAR WEIGHT
NECROSIS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANS
PATHOLOGICAL CHANGES
PEPTIDE HYDROLASES
PHENOBARBITAL
POLYCYCLIC AROMATIC HYDROCARBONS
PYRIMIDINES
RATS
RESPONSE MODIFYING FACTORS
RODENTS
SERINE PROTEINASES
SOMATIC CELLS
TOXICITY
TRACER TECHNIQUES
VERTEBRATES