6533b833fe1ef96bd129b912

RESEARCH PRODUCT

Enhancement of Nitro Reduction in Rat Liver Microsomes by Haemin and Haemoproteins

Regine KahlG. F. KahlH. G. JonenM. KuglerJ. H. Bonow

subject

HemeproteinsHot TemperatureHealth Toxicology and MutagenesisHemeIn Vitro TechniquesToxicologyBiochemistryHemoglobinschemistry.chemical_compoundRat liver microsomesmedicineAnimalsNitro reductionPharmacologyMyoglobinChemistryGeneral MedicineNitro CompoundsLigand (biochemistry)Stimulation ChemicalRatsOxygenBiochemistryMyoglobinNitrobenzoatesMicrosomes LiverMicrosomeNitroHeminFerricPotassium azideOxidation-Reductionmedicine.drug

description

1. Reductive metabolism of p-nitrobenzoic acid and neoprontosil in rat liver microsomes was studied in the presence of haemin, haemoglobin and myoglobin. 2. Microsomal nitro reduction is enhanced 4-fold in the presence of haemoglobin, whereas azo reduction is not affected. 3. Microsomal nitro reduction is enhanced to a similar extent by haemoglobin, haemin and boiled haemoglobin, whereas myoglobin is about half as active. 4. Maximal enhancement of microsomal nitro reductase activity by haemoglobin is achieved at high substrate concentration (6 mM) and low microsomal protein concentration (0.5--1.0 mg/ml). 5. Control microsomal nitro reduction as well as the haemoglobin-enhanced microsomal nitro reduction are inhibited completely by O2 and CO whereas potassium azide as a ligand of ferric haem iron is a less potent inhibitor.

yearjournalcountryeditionlanguage
1978-05-01Xenobiotica
https://doi.org/10.3109/00498257809060951