Cyclophosphamide-impaired regulation of hepatic heme metabolism.
In male rats hepatic cytochromes b5 and P-450 were reduced at different times after treatment with cyclophosphamide (CP) (200 mg/kg i.p. for 3 days). In contrast, microsomal heme did not change until 48 h after the last dose of CP, leading to accumulation of heme in a 'non-cytochromal' form. Parallel to the above changes the heme metabolism showed derangement: delta-aminolaevulinate synthase, the rate-limiting enzyme in heme synthesis, was depressed and heme oxygenase, the enzyme which catalyzes the oxidative degradation of heme, was increased.
D000624:5-Aminolevulinate Synthetase / Q000378:metabolism; D000818:Animals; D003520:Cyclophosphamide / Q000494:pharmacology*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D003573:Cytochrome b Group / Q000378:metabolism; D015786:Cytochromes b5; D006418:Heme / Q000378:metabolism*; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D051381:Rats
D003573:Cytochrome b Group; D006418:Heme; D003520:Cyclophosphamide; D015786:Cytochromes b5; D003577:Cytochrome P-450 Enzyme System; D006419:Heme Oxygenase (Decyclizing); D000624:5-Aminolevulinate Synthetase