The influence of the radiation syndrome on cytochrome P450-dependent monooxygenation in rat liver.
Cytochrome P-450 concentration and the monooxygenation activities of some cytochrome P-450 forms were determined in rat liver in the course of the acute radiation sickness. Ethylmorphine N-demethylation, ethoxycoumarin, ethoxyresorufin, and pentoxyresorufin O-dealkylation were used as indicator reactions. After radiation a distinct decrease in the hepatic biotransformation capacity can be observed, most pronounced at the climax of the radiation syndrome. Phenobarbital treatment (60 mg/kg b. m. at 3 consecutive days each) increases the concentration and the monooxygenase activities of some cytochrome P-450 forms. The degree of this induction effect is not altered at the third day after radiation, whereas at day 7 no significant inducibility can be observed.
Wölfle
G
G
Ernst Moritz Arndt University Greifswald, Germany.
Bleyer
H
H
Müller
D
D
Klinger
W
W
D015660:7-Alkoxycoumarin O-Dealkylase / Q000378:metabolism; D000818:Animals; D019363:Cytochrome P-450 CYP1A1; D019362:Cytochrome P-450 CYP2B1; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D005037:Ethylmorphine-N-Demethylase / Q000378:metabolism; D008099:Liver / Q000378:metabolism* / Q000528:radiation effects; D008297:Male; D010084:Oxidation-Reduction / Q000187:drug effects; D010088:Oxidoreductases / Q000378:metabolism; D010634:Phenobarbital / Q000494:pharmacology; D011833:Radiation Injuries, Experimental / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D015660:7-Alkoxycoumarin O-Dealkylase; D019363:Cytochrome P-450 CYP1A1; D019362:Cytochrome P-450 CYP2B1; D005037:Ethylmorphine-N-Demethylase; D010634:Phenobarbital