7-ALKOXYQUINOLINE O-DEALKYLATION BY MICROSOMES FROM HUMAN LIVER AND PLACENTA

1 The O-dealkylation of seven 7-alkoxyquinoline derivatives by human hepatic and placental microsomes and the effect of maternal cigarette smoking on placental 7-alkoxyquinoline metabolism was studied. 2 None of several monoclonal antibodies to isoenzymes of cytochrome P450 had a clear effect on metabolism of the compounds by liver microsomes. 3 Maternal cigarette smoking induced the O-dealkylation of all of the 7-alkoxyquinoline derivatives, being greatest for 7-butoxy- and 7-benzyloxyquinoline. 4 Placental 7-alkoxyquinoline metabolism induced by smoking was partially inhibited by the monoclonal antibody 1-7-1 raised against 3-methylcholanthrene-induced rat liver P450. 5 None of the 7-alkoxyquinoline O-dealkylations could be assigned specifically to any known P450 isoenzyme in human liver or placenta.