Metabolic activation of halogenated hydrocarbons in the conjunctival epithelium and excretory ducts of the intraorbital lacrimal gland in mice.
Autoradiographic studies were performed to determine the localization of irreversibly bound radioactivity in the eyes and accessory structures of mice exposed to 14C-labelled organic solvents in vivo or in vitro. A selective localization of bound radioactivity was observed in the conjunctival epithelium of mice given i.v. injections of 1,2-dibromoethane, chloroform, carbon tetrachloride or bromobenzene. Similar results were observed after instillation of chloroform or carbon tetrachloride in the conjunctival sac and after incubation of eyelids with the labelled compounds in vitro. A high level of irreversibly bound radioactivity was also observed in the excretory ducts of the intraorbital lacrimal glands of mice exposed to 1,2-dibromoethane in vivo and in vitro. After incubation of 14C-labelled 1,2-dibromoethane or chloroform with homogenates prepared from rat conjunctiva, the presence of irreversibly protein-bound radioactivity was detected. The results indicate that the conjunctival epithelium can metabolically activate halogenated organic solvents into products that bind to the tissue. The significance of a metabolic activation of chemicals in the pathogenesis of chemically induced lesions in the conjunctiva merits further attention.
Brittebo
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EB
Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala.
Eriksson
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C
Brandt
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I
D000818:Animals; D001345:Autoradiography; D001711:Biotransformation; D001969:Bromobenzenes / Q000493:pharmacokinetics; D002251:Carbon Tetrachloride / Q000493:pharmacokinetics; D002725:Chloroform / Q000493:pharmacokinetics; D003228:Conjunctiva / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism; D015946:Ethylene Dibromide / Q000493:pharmacokinetics; D005143:Eyelids / Q000378:metabolism; D005260:Female; D006846:Hydrocarbons, Halogenated / Q000493:pharmacokinetics*; D066298:In Vitro Techniques; D007765:Lacrimal Apparatus / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D051381:Rats; D011919:Rats, Inbred Strains
D001969:Bromobenzenes; D006846:Hydrocarbons, Halogenated; D015946:Ethylene Dibromide; D002725:Chloroform; D002251:Carbon Tetrachloride; C032036:bromobenzene