RT Journal Article
SR Electronic
T1 BILIARY EXCRETION OF 3-METHYLCHOLANTHRENE AS CONTROLLED BY ITS METABOLISM
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 420
OP 426
VO 183
IS 2
A1 WALTER G. LEVINE
YR 1972
UL http://jpet.aspetjournals.org/content/183/2/420.abstract
AB The carcinogen, 3-methylcholanthrene (MC), is converted to polar metabolites by hepatic drug-metabolizing enzymes of the rat. After an i.v. injection of 3H-MC, radioactivity is readily recovered in the bile in the form of 3H-MC metabolites. Biliary excretion of 3H-MC metabolites is accelerated by pretreatment with inducers of drug metabolism (3,4-benzpyrene, phenobarbital) and retarded by pretreatment with inhibitors of drug metabolism (SKF 525A, piperonyl butoxide, metyrapone). These agents have a similar effect on the rate of appearance of 3-MC metabolites in the blood. If 3H-MC metabolites are injected, their rate of excertion is far greater than that seen after the injection of 3H-MC. This rate is not affected by inducers nor inhibitors of drug metabolism. The evidence supports the concept that metabolism is the rate-limiting step in the biliary excretion of 3H-MC. © 1972 by The Williams & Wilkins Co.