Cytochrome P 45o

The spectral properties of a P-450 preparation from adrenocortical mitochondria were compared with those of both other hemoproteins and model compounds to examine the possibility suggested by previous authors that the mercaptide anion (thiolate anion, RS-) of a cysteine residue might be one of the axial ligands of P-45O. 1. The following features were found in addition to the well known anomalous spectral characteristics of P-450. The Soret band of the ferrous form was at anomalously short wavelengths compared with those of other ferrous high-spin hemoproteins...

Overt clinical disease from undue lead exposure has become a relatively rare phenomenon in adult populations. However, exposure situations that may result in subclinical disease are not uncommon in various occupational settings. Five demolition workers, dismantling an old iron structure covered with lead-content paint, were studied. The use of cutting torches resulted in lead fumes, with significant exposure, albeit without gross 'lead poisoning." All five workers showed biochemical manifestations of chronic lead intoxication-that is, elevated blood lead level, inhibition of delta-aminolevulinic acid dehydratase (ALA-D), and elevated erythrocytic protoporphyrin concentration (PROTO)...

The polychlorinated biphenyls (PCBs) represent a newly recognized and widely distributed category of environmental pollutants whose biologic impact on animals and man may be both substantial and highly detrimental. The pharmacologic effects of these agents on enzymes in the liver which metabolize drugs and other foreign compounds, such as carcinogens, are powerful and long lasting. PCBs mimic the effects produced on these enzymes by drugs, such as phenobarbital, and carcinogens, such as 3-methylcholanthrene...

18-Hydroxylation of deoxycorticosterone was studies with rat or bovine adrenal mitochondria or with reconstituted systems obtained from these fractions. The reconstituted systems consisted of a partially purified preparation of cytochrome P-450 from rat adrenals and a partially purified NADPH-cytochrome P450 reductase preparation from bovine adrenals. In some experimenta a soluble cytochrome P-450 fraction from bovine adrenals was used. Adrenodoxine and adrenodoxine reductase were shown to be the active components of the NADPH-cytochrome P-450 reductase preparation...