STUDIES ON THE INDUCTION BY EXTRACTS FROM AIRBORNE-PARTICULATES OF BENZO(A)PYRENE HYDROXYLASE AND THE BINDING OF BENZO(A)PYRENE TO DNA IN THE RAT LUNG INVIVO AFTER PERTRACHEAL ADMINISTRATION

  • 1 January 1981
    • journal article
    • research article
    • Vol. 174  (3) , 260-273
Abstract
A method was described for the administration of suspended material into the rat lung. The rat was narcotized by CO2/air, the trachea was punctured and the suspension sucked into the lung by the inhaled air (pertracheal administration, pta). BaP [benzo[a]pyrene] was eliminated from the lung rapidly, while metabolites persisted for a longer period. The radioactivity detected in the blood was attributed predominantly to metabolites but a small fraction was unmetabolized BaP. The activity of benzo[a]pyrene hydroxylase was induced in the lung after pta of extracts from airborne particulate matter. The activity increased depending on the dose until a plateau of activity was reached at high doses; pta administered BaP was bound to DNA of the lung. Pretreatment with extracts pta enhanced the binding. After enzymatic digestion of DNA BaP-nucleoside adducts were detected by HPLC [high performance liquid chromatography]. According to data published in the literature, the adducts were supposed to be derived from BaP-phenols and BaP-diolepoxides. The components of airborne particulates modified the activity of metabolizing enzymes and increased the rate of formation of adducts in the lung in vivo.