Abstract
Rats, mice, hamsters, guinea pigs, and rabbits were used in a preliminary study to select a model animal for more detailed study of xenobiotic-metabolizing enzymes in intestine. The xenobiotic oxidation reactions studied included hydroxylation of aniline, biphenyl, and benzpyrene and N-demethylation of ethylmorphine. NADPH-cytochrome c reductase activity and cytochrome P-450 were measured as parts of the microsomal electron transport system. The xenobiotic-metabolizing enzymes were present in livers of all the species and varied in activity over a 2- to 6-fold range among species for any given enzyme. In intestines from mice, rats, guinea pigs, and hamsters, either some of the enzymes were absent or had very low activity which would require very sensitive methods for detection. The rabbit emerged as the best animal for studying intestinal microsomal xenobiotic metabolism since all xenobiotic-metabolizing enzymes studied were present in easily measurable quantities.
Footnotes
- Received May 17, 1974.
- Copyright © 1974 by The American Society for Pharmacology and Experimental Therapeutics