Glucuronidation and sulfation in subcellular fractions and in the isolated perfused rabbit lung: influence of ethanol.
Glucuronidation and sulfation of 1-naphthol, 7-hydroxycoumarin, 4-nitrocatechol and phenolphthalein were studied in rabbit lung and liver. Pulmonary UDP-glucuronyltransferase and sulfotransferase activities in subcellular fractions were approximately 20-50% of those determined in the liver. Ethanol did not markedly induce these enzymes in either tissue. Glucuronidation and sulfation of 1-naphthol and 7-hydroxycoumarin were also studied in the isolated perfused rabbit lung as an intact cell model. Neither glucuronidation nor sulfation of 1-naphthol was observed. The absence of conjugate formation was due neither to the presence of beta-glucuronidase and/or sulfatase, nor to alternative biotransformation pathways. About 35% of the initial 7-hydroxycoumarin was conjugated, the majority being sulfate conjugate (14.4 nmol/h) with only minor amounts (0.12%) of the glucuronide. These results indicate the importance of studying both whole organ and in vitro metabolism.
Yang
C M
CM
Department of Pharmacology and Toxicology, School of Pharmacy and Pharmacal Sciences, Purdue University, West Lafayette, Ind.
Carlson
G P
GP
D000818:Animals; D002396:Catechols / Q000378:metabolism; D002855:Chromatography, Thin Layer; D000431:Ethanol / Q000494:pharmacology*; D005965:Glucuronates / Q000378:metabolism; D014453:Glucuronosyltransferase / Q000378:metabolism; D066298:In Vitro Techniques; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D008168:Lung / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D008748:Methylcholanthrene / Q000494:pharmacology; D009284:Naphthols / Q000378:metabolism; D010634:Phenobarbital / Q000494:pharmacology; D020113:Phenolphthalein; D010635:Phenolphthaleins / Q000378:metabolism; D011817:Rabbits; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism; D015238:Sulfotransferases / Q000378:metabolism; D014468:Umbelliferones / Q000378:metabolism
D002396:Catechols; D005965:Glucuronates; D009284:Naphthols; D010635:Phenolphthaleins; D013431:Sulfates; D014468:Umbelliferones; D000431:Ethanol; D008748:Methylcholanthrene; C031477:7-hydroxycoumarin; D020113:Phenolphthalein; D014453:Glucuronosyltransferase; D015238:Sulfotransferases; C001833:4-nitrocatechol; D010634:Phenobarbital