METABOLISM OF BENZIDINE BY A PROSTAGLANDIN-MEDIATED PROCESS IN RENAL INNER MEDULLARY SLICES

  • 1 January 1980
    • journal article
    • research article
    • Vol. 215  (2) , 401-406
Abstract
Renal inner medullary slices [from rabbits] were used to investigate the metabolism and subsequent binding to tissue of the carcinogen [14C]-benzidine metabolite(s) and the effect of benzidine on radioimmunoassayable prostaglandin (PG) E2 synthesis. Benzidine elicited a dose-dependent, reversible inhibition of PGE2 synthesis. Aspirin inhibition of PGE2 synthesis was not reversible. Binding of [14C]-benzidine metabolite(s) to medullary tissue was observed. This binding was increased by arachidonic acid. Arachidonic acid-mediated binding was prevented by inhibitors of prostaglandin endoperoxide synthetase. Metyrapone and SKF-525A [proadifen hydrochloride], inhibitors of mixed function oxidase activity, did not inhibit binding of benzidine metabolite(s). Fatty acids which are not substrates for PG endoperoxide synthetase did not incease binding. The results are consistent with previous studies demonstrating inner medullary microsomal cooxidative metabolism of benzidine by PG endoperoxide synthetase and document the cooxidative process proceeds in an intact cell preparation, the tissue slice. The renal inner medulla is a potential site for the cooxidative metabolism of drugs and xenobiotics which require activation before eliciting their toxic effects on the urinary tract.