biotransformation of benzo[a]pyrene (bap) in the presence of microsomal fractions derived from liver and epiderm of adult and weanling rats was examined. the aim of this study was to evaluate the effect of age on the capacity of two organs in transformation of bap. subcellular fractions were prepared from skin and liver by ultracentrifugation and were used as the source of bap metabolizing enzy...

1. A method for the subcellular fractionation of intestinal mucosa is described. The subcellular fractions were characterized by electron microscopy and by deternining the distributions of cytochrome oxidase and alkaline phosphatase in the subcellular fractions. 2. The subcellular distribution of peptidases hydrolysing L-leucylglycine and glycylglycine has been determined in intestinal mucosa. ...

The level of phosphodiesterase (PDE) activity is lower in collagenase-isolated human fat cells than in adipose tissue fragments. The inhibition is not species-specific since collagenase also inhibits PDE in rat adipose tissue and bovine heart. In subcellular fractions from isolated fat cells, the PDE activities were lowest in the plasma membrane-enriched fractions and highest in the cytosolic f...

Neutrophil gelatinase-associated lipocalin (NGAL) is a novel 25-kD protein of human neutrophils, that is in part covalently complexed with neutrophil gelatinase. However, both NGAL and gelatinase exist mainly in forms not associated with each other. An explanation for this phenomenon might be that the unassociated proteins reside in different subcellular compartments. The aim of the present stu...

The fluorometric coupled enzyme assay to measure phosphatidic acid (PA) involves the solubilization of extracted lipids in Triton X-100, deacylation, and the oxidation of PA-derived glycerol-3-phosphate to produce hydrogen peroxide for conversion of Amplex Red to resorufin. The enzyme assay is sensitive, but plagued by high background fluorescence from the peroxide-containing detergent and inco...

Determinations of scrapie activity in subcellular fractions from infected hamster brains through the asymptomatic and symptomatic course of infection revealed the presence of substantial amounts of scrapie infectivity in the 100,000 X g supernatant fractions, indicating that association with physically discernible membrane structures is not necessary for the transmission of the scrapie agent. A...