Send to

Choose Destination
Xenobiotica. 1988 Aug;18(8):983-9.

On the sulphoxidation of cimetidine and etintidine by rat and human liver microsomes.

Author information

Institute of Legal Medicine, University of Hamburg, F.R. Germany.


1. Sulphoxidation of cimetidine and etintidine was investigated by in vitro assays with liver microsomes from untreated 5,6-benzoflavone- and phenobarbital-pretreated rats as well as with human liver microsomes. The formation rate of cimetidine sulphoxide and etintidine sulphoxide with liver microsomes of normal or pretreated rats reached to 1.1 and 0.9 nmol/min mg microsomal protein, respectively. 2. Inhibition experiments with carbon monoxide and n-octylamine indicated that this sulphoxidation is catalyzed by cytochrome(s) P-450, whereas flavin-containing monooxygenase and/or non-enzymatic reactions (via peroxides) seems not to be involved: no inhibition was observed by methimazole, N,N-dimethylaniline, preheating or glutathione and EDTA. 3. With human liver microsomes the cytochrome P-450-dependent sulphoxidation accounted for no more than 40% of the total oxidation.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Taylor & Francis
Loading ...
Support Center