Acta Biol Med Ger. 1982;41(10):935-9.  

Effect of repeated carbon monoxide exposure to rats on cytochrome P-450
concentration and activities of monooxygenases in the liver.

Pankow D, Schiller F, Muller D.

To determine the possible role of cytochrome P-450 in the adaptation response of
an organism to chronic carbon monoxide exposure, rats received 4, 15 or 30
subcutaneous CO injections (7.2 mmol/kg body mass; maximal COHb concentration
about 56%). The concentration of cytochrome P-450 is significantly reduced after
4 injections. This effect is no longer evident following 15 or 30 CO injections,
which produced distinct increases of the total hemoglobin concentration.
Ethylmorphine N-demethylation is distinctly inhibited after 4, 15 and 30 CO
injections, whereas the initial inhibition of ethoxycoumarin O-deethylation
disappears after 30 CO administrations. Ethoxyresorufin O-deethylation is only
slightly influenced by CO.

PMID: 6984995 [PubMed - indexed for MEDLINE]