Incorporation of haemoglobin haem into the rat hepatic haemoproteins tryptophan pyrrolase and cytochrome P-450
| Autor: | J L Gollan, J F Wyman, W Settle, M A Correia, G C Farrell |
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| Rok vydání: | 1986 |
| Předmět: |
Male
Oxygenase Porphyrins Hemeprotein Cytochrome Heme Biochemistry Hemoglobins chemistry.chemical_compound Cytochrome P-450 Enzyme System polycyclic compounds Animals Bile Cytochrome c oxidase Molecular Biology Methemoglobin biology digestive oral and skin physiology Cytochrome P450 Rats Inbred Strains Cell Biology Metabolism Tryptophan Oxygenase Rats Perfusion Liver chemistry biology.protein Allylisopropylacetamide Hemoglobin Research Article |
| Zdroj: | Biochemical Journal. 238:837-846 |
| ISSN: | 1470-8728 0264-6021 |
| DOI: | 10.1042/bj2380837 |
| Popis: | After its administration to intact rats, haemoglobin haem was incorporated into hepatic tryptophan pyrrolase as shown by the marked increase in functional constitution of this enzyme. Incorporation of haemoglobin haem into cytochrome P-450 was demonstrated in intact rats and in the isolated rat liver perfused with haemoglobin-free medium. In both systems, haemoglobin haem restored cytochrome P-450 content and its dependent mixed-function-oxidase activity after substrate-induced destruction of the cytochrome P-450 haem moiety. Further confirmation that haemoglobin haem could be incorporated prosthetically into cytochrome P-450 was achieved by administration of [3H]haemoglobin to rats and subsequent isolation and characterization of radiolabelled substrate-alkylated products of cytochrome P-450 haem. Our findings indicate that, although hepatic uptake of parenteral haemoglobin is slower than that of haem, it appears to serve as an effective haem donor to the intrahepatic ‘free’ haem pool. Thus parenteral haemoglobin may warrant consideration as a therapeutic alternative to haem in the acute hepatic porphyrias. |
| Databáze: | OpenAIRE |
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