The nitrated polycyclic aromatic hydrocarbon 1-nitropyrene is a ubiquitous environmental pollutant. The role of cytochromes P-450 in the human metabolism of [3H]-1-nitropyrene was investigated using human liver microsomes. The range of microsomal metabolism from 16 individual liver specimens was 0.13 to 0.99 nmol/min/mg protein. Using 3 microsomal samples exhibiting different maximal velocities...

Fifteen peptides, ranging in length from 6 to 31 amino acids and corresponding in sequence to portions of the major phenobarbital-inducible form of rat liver cytochrome P-450 (P-450 PB-4), were previously synthesized chemically and used to prepare site-specific rabbit antibodies (Frey, A. B., D.J. Waxman, and G. Kreibich, 1985, J. Biol. Chem., 260:15253-15265). The antipeptide antibodies were a...

The current study was designed to test the role of cytochrome P-450 in hydrogen peroxide-induced cytotoxicity, and to determine whether it may serve as a source of catalytic iron. Hydrogen peroxide led to iron release (as measured by iron/bathophenanthroline complex) from the microsomes prepared from LLC-PK1 cells. Cimetidine, which inhibits cytochrome P-450 by interacting with the heme iron, s...

The administration of spironolactone, a diuretic steroid, is known to cause a depletion of microsomal cytochrome P-450 in those tissues which have a high activity of steroid 17a-hydroxylase. In this paper, studies are presented to indicate that the sulfur atom located at the carbon 7-a position on the spironolactone molecule is required for the loss of the heme and apoproteins of adrenal or tes...

Biochar is a promising option for improving soil fertility and agricultural productivity. The potential of biochar specific purposes depends on its physical chemical characteristics. avocado seed widely available as leftover after the fleshy part used food byproduct avocado-oil producing agro-industries in Ethiopia. Its an agronomic purpose has not been studied. objective this study was to comp...

The roles of two species of cytochrome P-450, the major cytochrome P-450 components of liver microsomes of phenobarbital-treated rats (PB-P-450) and of 3-methylcholanthrenetreated rats (MC-P-448), in the metabolism of 2-acetylaminofluorene were studied in rat liver microsomes in vitro. 2-Acetylaminofluorene was incubated with the microsomes of rats treated with three different inducers of monoo...

The nitrated polycyclic aromatic hydrocarbon 1-nitropyrene is a ubiq uitous environmental pollutant. The role of cytochromes P-450 in the human metabolism of [3II]-l-nitropyrene was investigated using human liver microsomes. The range of microsomal metabolism from 16 indi vidual liver specimens was 0.13 to 0.99 nmol/min/mg protein. Using 3 microsomal samples exhibiting different maximal velocit...

el nl. [ 5 ] on to nylon (Hybond-N, Amersham). Dot blots using a BRL apparatus were on to nitrocellulose (BRL) for RNA and nylon (Amersham) for DNA. Gene probes isolated from rat cDNA libraries corresponding to two members of cytochrome 1’-450 superfamily, namely a 1.2 kb fragment of P-450 lVAl (1’-450 LAW, 1’452) and a 1.1 kb fragment of P-450 RLM6 (probably the same as the alcohol inducible 1...

Reactive oxygen species are a major cause of damage occurring in ischemic tissue after reperfusion. During reperfusion transitional metals such as iron are required for reactive oxygen species to mediate their major toxic effects. Xanthine oxidase is an important source of reactive oxygen species during ischemia-reperfusion injury, but not in all organs or species. Because cytochrome P-450 enzy...

The NADPH-dependent reduction of rat hepatic microsomal cytochrome P-450 has been studied as a function of temperature. In the temperature range 4-37’ the reduction reaction was found to be biphasic and composed of two concurrent first order processes. This phenomenon was observed with microsornes from untreated and phenobarbital-induced animals in the presence or absence of exogenous Type I su...