Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:1.14.99.3 (
heme oxygenase
)
4,196
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Pretreatment of rats with zinc-protoporphyrin, which has shown to be a potent competitive inhibitor of
heme oxygenase
, resulted in the inhibition of bromobenzene-mediated induction of
heme oxygenase
and decreases of the cytochrome P-450 content, aminopyrine demethylase and aniline hydroxylase activities. Such an inhibitory effect of zinc-protoporphyrin on the induction of
heme oxygenase
and concomitant decreases of drug-metabolizing enzymes occurred in a dose-dependent manner with complete inhibition of these effects at a dose of 40 mumol/kg. The effects of zinc-protoporphyrin were also observed in thioacetamide- and
BCG
-treated rats and ascitic tumor AH 66-bearing rats. Likewise, a decrease of cytochrome b5 content observed under these experimental conditions was also restored significantly by zinc-protoporphyrin. These results strongly suggest that the induction of
heme oxygenase
is a primarily important early event which consequently leads to the decrease in cytochrome P-450 content and associated enzyme activities.
...
PMID:Inhibitory effect of zinc-protoporphyrin on the induction of heme oxygenase and the associated decrease in cytochrome P-450 content in rats. 338 37
The alterations of various enzymes responsible for drug metabolism and heme metabolism were examined in the liver of female rats treated with
Bacillus Calmette-Guerin
(
BCG
) and Corynebacterium parvum (CP). Hepatic drug metabolizing enzyme activities and microsomal cytochrome P-450 and b5 content were significantly decreased for up to 15 and 10 d by a single i.v. administration of
BCG
and CP, respectively. In contrast, microsomal
heme oxygenase
activity was markedly increased after
BCG
and CP treatment and the increased enzyme activity was sustained in parallel with the decrease of drug metabolizing enzymes. Both
BCG
and CP also caused a significant decrease of delta-aminolevulinic acid synthetase activity shortly after their administrations. The decreased enzyme activity returned to normal levels by 12 h after the treatment of rats with
BCG
and CP. In addition, hepatosplenomegaly was observed in
BCG
and CP treated rats. Dose related changes of these microsomal enzymes were seen following the administration of
BCG
and CP. Additionally, there were sex differences in the effects of
BCG
and CP on the alteration of microsomal enzymes, female rats being more sensitive than male rats. These results suggest that the decrease of cytochrome P-450 and b5 content and drug metabolizing enzyme activities by
BCG
and CP could be related, at least in part, to the prolonged increase of
heme oxygenase
activity, that may lead to the increased breakdown of heme available for the synthesis of these hemoproteins.
...
PMID:A sustained increase of microsomal heme oxygenase activity following treatment of rats with Bacillus Calmette-Guerin and Corynebacterium parvum: its possible relation to the decrease of cytochrome P-450 content. 384 63
