[The role of heme in the regulation of tryptophan-2,3-dioxygenase activity and content of cytochrome P-450 in rat liver].
The effects of exogenous heme on the activity of delta-aminolevulinate synthase, heme oxygenase, tryptophan-2.3-dioxygenase and microsomal cytochrome content in rat liver were studied. It was shown that hemin chloride diminishes the delta-aminolevulinate synthase activity and provokes heme oxygenase induction. This is paralleled with the induction of the tryptophan 2.3-dioxygenase apoenzyme and an increase in the saturation of the enzyme with heme. The cytochrome b5 content does not change thereby, whereas that of cytochrome P-450 shows a decrease. Upon combined administration of actinomycin D and hemin the cytochrome P-450 level is markedly increased. Actinomycin D by itself has no effect on the hemoprotein concentration. It is concluded that the increase in the cytochrome P-450 level results from the activation of heme-induced mRNA translation.
Kaliman
P A
PA
Nikitchenko
I V
IV
Manandkhar
S P
SP
D000624:5-Aminolevulinate Synthetase / Q000378:metabolism*; D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D003609:Dactinomycin / Q000494:pharmacology; D004347:Drug Interactions; D006418:Heme / Q000494:pharmacology*; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D006420:Hemeproteins / Q000378:metabolism; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D013056:Spectrophotometry, Ultraviolet; D014366:Tryptophan Oxygenase / Q000378:metabolism*
D006420:Hemeproteins; D003609:Dactinomycin; D006418:Heme; D003577:Cytochrome P-450 Enzyme System; D003513:Cycloheximide; D014366:Tryptophan Oxygenase; D006419:Heme Oxygenase (Decyclizing); D000624:5-Aminolevulinate Synthetase
Rol' gema v reguliatsii triptofan-2,3-dioksigenaznoĭ aktivnosti i soderzhaniia tsitokhroma P-450 v pecheni krysy.