BACKGROUND To assess the effects of single polycyclic aromatic hydrocarbons (PAHs) on solid tumor initiation, and investigate their roles in immune response regulation. MATERIAL AND METHODS Mice (100) were randomly divided into 5 groups (n=20) to be intraperitoneally injected with 10 daily doses of DMSO (control), anthracene (50 mg/kg), benzo-(a)-pyrene (10 mg/kg), benzo-(a)-pyrene (20 mg/kg)...

The exposure of Estonian cokery workers to polynuclear aromatic hydrocarbons at an oil shale processing plant was assessed by occupational hygiene and biomonitoring measurements. To assess the external dose of exposure to polynuclear aromatic hydrocarbons, pyrene and benzo[a]pyrene concentrations were measured from the breathing zone of workers during a workshift. Skin contamination with pyrene...

NAD(P)H:quinone oxidoreductase 1 (NQO1) is a cytosolic protein that catalyzes metabolic detoxification of quinones and protects cells against redox cycling and oxidative stress. NQO1-null mice deficient in NQO1 protein showed increased sensitivity to 7,12-dimethylbenz(a)anthracene- and benzo(a)pyrene-induced skin carcinogenesis. In the present studies, we show that benzo(a)pyrene metabolite ben...

A method capable of determining 13 PAHs (acenaphthene, anthracene, benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, chrysene, dibenzo[ah]anthracene, fluoranthene, fluorene, indene[1,2,3-cd]pyrene, phenanthrene and pyrene) in a mixture of 16 EPA PAHs by second derivative synchronous spectrofluorometry in the constant wavelength mode was developed. It has not been p...

The effect of flavone and 7,8-benzoflavone on the metabolism of benzo[a]pyrene to fluorescent phenols by five cytochrome P-450 isozymes obtained from rabbit liver microsomes was determined. Benzo[a]pyrene metabolism was stimulated more than 5-fold by the addition of 600 microM flavone to a reconstituted monooxygenase system consisting of NADPH, cytochrome P-450 reductase, dilauroylphosphatidylc...

The addition of benzo(a)pyrene to cells obtained from Syrian hamster embryo cultures that had been plated to produce discrete colonies resulted in transformation. Altered colonies were not seen in controls. Prior irradiation of hamster embryo cells increased the transformation by benzo(a)pyrene, both per cell and per total colony. Maximum enhancement occurred when benzo(a)pyrene was added 48 hr...

We propose that the cellular burden of certain carcinogens may be mitigated by P-glycoprotein (P-gp), the putative drug effiux pump. In a series of multidrug resistant human breast cancer MCF-7 cells with increasing P-gp expression we examined this hypothesis using benzo(a)pyrene, a widely distributed environmental and dietary carcinogen. We found that multidrug resistant cells were cross-resis...

The metabolism and covalent binding of the environmen tal carcinogen benzo(a)pyrene, a constituent of cigarette smoke, has been determined in isolated perfused lungs of shamand cigarette smoke-exposed and 3-methylcholanthrene-pretreated male Wistar rats. Rats were exposed to cigarette smoke for 1 hr daily for either 1 or 10 days. Benzo(a)pyrene (2 nmoles) was instilled intratracheally, and meta...

The metabolism and covalent binding of the environmen tal carcinogen benzo(a)pyrene, a constituent of cigarette smoke, has been determined in isolated perfused lungs of shamand cigarette smoke-exposed and 3-methylcholanthrene-pretreated male Wistar rats. Rats were exposed to cigarette smoke for 1 hr daily for either 1 or 10 days. Benzo(a)pyrene (2 nmoles) was instilled intratracheally, and meta...

Present study was undertaken to examine the extent of Polycyclic Aromatic Hydrocarbons (PAHs) contamination in neighbourhood lithospheric environment of landfill site situated in eastern outer edge of Kolkata metropolitan city in West Bengal, India, along with its sources identification, spatial distribution and probabilistic cancer risks to residents. The collection and analytical tests were p...