The direct spectrophotometric observation of benzo(a)pyrene phenol formation by liver microsomes. (1/611)
Optical spectral repetitive scan analysis during the oxidative metabolism of benzo(a)pyrene by liver microsomal suspensions reveals the time-dependent formation of an intermediate(s) of which the visible spectra resemble those of several benzo(a)pyrene phenols. Liver microsomes from 3-methylcholanthrene-treated rats showed a greater rate of formation of the phenols than did microsomes from control animals; the rate of formation catalyzed by liver microsomes from phenobarbital-pretreated rats was intermediate. When 3-hydroxybenzo(a)pyrene was used as a standard for comparison of activity, the rates of formation of phenols were compared when measured by fluorometric, spectrophotometric, or high-pressure liquid chromatographic analytical techniques. An epoxide hydrase inhibitor, 1,1,1-trichloropropene-2,3-oxide, enhanced phenol formation regardless of the source of liver microsomes, and 7,8-benzoflavone inhibited control and 3-methylcholanthrene-induced microsomal metabolism of benzo(a)pyrene, 7,8-Benzoflavone did not effect benzo(a)pyrene metabolism by liver microsomes from phenobarbital-pretreated rats. The effect of inhibitors on the spectrophotometric assay correlates well with the results obtained from benzo(a)pyrene metabolite analysis using high-pressure liquid chromatography. (+info)Differences in benzo(a)pyrene metabolism between rodent liver microsomes and embryonic cells. (2/611)
Differences in benzo(a)pyrene metabolite pattern have been shown by rodent liver microsomes (Sprague-Dawley) and rodent embryo cells from Syrian hamsters and NIH Swiss mice. Rodent liver induced by methylcholanthrene shows marked quantitative variation between species. Additional pattern changes were found in mouse and hamster embryo secondary cultures with a reduction of the K-region metabolites and a marked increase in 9-hydroxybenzo(a)-pyrene. These results are indicative of a region-specific attack on the carcinogen by the cell monooxygenases which is distinct from the liver attack of microsomal enzymes on benzo(a)pyrene. These results suggest that activation and detoxification of benzo(a)pyrene may be species and tissue variable, and susceptibility and resistence to malignant transformation may be predicted on induction of a fortuitous combination of intermediate metabolic steps. (+info)Formation in isolated rat liver microsomes and nuclei of benzo(a)pyrene metabolites that bind to DNA. (3/611)
The hepatic nuclear fraction isolated from 3-methylcholanthrene (MC)-treated rats contained enhanced levels of cytochrome P-450 and aryl hydrocarbon hydroxylase [benzo(a)pyrene (BP) monooxygenase], whereas the activities of epoxide hydrase and reduced nicotinamide adenine dinucleotide phosphate-cytochrome c reductase and the concentration of cytochrome b5 were not altered. The metabolite pattern of BP was investigated by using high-pressure liquid chromatography and was found to be similar in nuclei and microsomes from MC-treated rats. After incubation of the nuclear fraction with [3H]BP and reduced nicotinamide adenine dinculeotide phosphate, radioactivity was found to be associated with nuclear DNA and the extent of binding was markedly enhanced by pretreatment of the animals with MC. Binding was strongly inhibited by a-napthoflavone but was not influenced by 1,1,1-trichloropropene-2,3-oxide, an inhibitor of epoxide hydrase. In the presence of microsomes from MC-treated rats, increased binding of BP to DNA was observed in nuclei from both control and MC-treated rats; moreover, when the nuclear DNA was replaced by a corresponding amount of calf thymus DNA, the extent of binding was severalfold enhanced. In contrast to nuclei from control rats, the nuclear fraction from MC-treated rats showed an increase in bound radioactivity when incubated with a microsome-free supernatant, obtained by incubating microsomes from MC-treated rats with [3H]BP. The increase in extent of binding was eliminated in the presence of menadione or alpha-naphthoflavone. It is suggested that under the conditions used here the following different processes may have contributed to the total incorporation of BP products into nuclear DNA: (a) formation of DNA-binding products derived from BP by nuclear aryl hydrocarbon hydroxylase; (b) formation of DNA-binding products from microsomal BP metabolites by nuclear aryl hydrocarbon hydroxylase; and (c) direct transfer of reactive microsomal metabolites to nuclear DNA. (+info)Nonenzymatic reduction of benzo(a)pyrene diol-epoxides to trihydroxypentahydrobenzo(a)pyrenes by reduced nicotinamide adenine dinucleotide phosphate. (4/611)
The diol-epoxide r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene is a potent mutagen and possibly the ultimate carcinogenic form of benzo(a)pyrene. A (7/8,9)-trihydroxy-7,8,9,10,10-pentahydrobenzo(a)pyrene is formed from the diol-epoxide r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydroxybenzo(a)pyrene by reduction with reduced nicotinamide adenine dinucleotide phosphate. Its formation is linear with reduced nicotinamide adenine dinucleotide phosphate concentration and does not require the presence of enzyme. A (7,9/8)-trihydroxy-7,8,9,10,10-pentahydrobenzo(a)pyrene is similarly formed from the diol-epoxide r-7,t-8-dihydroxy-c-9,10-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene by reduction with reduced nicotinamide adenine dinucleotide phosphate. The structures of the trihydroxypentahydrobenzo(a)pyrenes were established by their ultraviolet absorption and mass spectra and their reaction with potassium triacetylosmate. (+info)Use of tracheal organ cultures in toxicity testing. (5/611)
Fragments of tracheal epithelium alone or in continuity with connective tissues, can be maintained in culture medium and used for short term or long term studies of toxicity of a variety of chemicals. Large numbers of uniform cultures are prepared with the aid of a slicing device or by application of simple method for dissecting sheets of epithelium free from underlying cartilage. The cultures may be placed in an exposure chamber-incubator mounted on a microscope stage and monitored continually for ciliostasis and exfoliation of cells. Morphology is further studied by fixation of selected specimens and preparation for light microscopy and electron microscopy. Synthetic functions are evaluated by autoradiographic measurement of incorporation of radioactive precursors into macromolecules and other dynamic features are indirectly assessed by histochemical and histoenzymatic methods. Short-term studies using these several techniques have shown that ciliostasis does not correlate with cell injury in all instances, and a long-term study has demonstrated dose dependence of a cytotoxic agent when duration of culture viability is measured. The method lends itself to a broad range of investigations in which dose, period of exposure, and role of cofactors must be independently and quantitatively assessed. (+info)Biochemical studies of isolated hamster tracheal epithelium. (6/611)
The epithelial lining of respiratory air passageways is a primary target tissue for toxicity and carcinogenesis in man and in animal models of human disease. The importance of this target tissue was the basis for development of methods to study its biochemistry, and with this information to distinguish the unique properties of this tissue from properties common to all cell types. Biochemical methods employed labeling of macromolecules in isolated hamster treacheas during brief (less than 4 hr) incubation in vitro. Studies of RNA metabolism in isolated tracheas demonstrated a pattern of maturation of ribosomal RNA like that shown for other cell types. Alterations in RNA metabolism were observed in isolated tracheas obtained from vitamin A-deficient hamsters and hamsters previously treated by intratracheal administration of benzo[a]pyrene (BP) plus ferric oxide (Fe2O3) in vivo. Studies with toyocamycin, actinomycin D, and alpha-amanitin, all inhibitors of RNA metabolism, were performed to characterize the class of RNA molecules with a decreased proportion of labeling in tracheas from vitamin A deficient hamsters. In another series of experiments, BP was shown to bind to DNA in epithelial cells of isolated tracheas. The quantity of BP binding was increased by prior intratracheal treatment of hamsters with BP plus Fe2O3 in vivo, this induced binding was inhibited by addition of 7,8-benzoflavone to the incubation medium. Increased BP binding was also observed in isolated tracheas from hamsters believed to be in states of increased susceptibility to respiratory carcinogenesis in vivo. The results show that biochemical studies are feasible with this tissue. Furthermore, a number of questions of importance with regard to this target epithelium are best studied directly in its constituent cells. (+info)Comparison of cytochrome P450- and peroxidase-dependent metabolic activation of the potent carcinogen dibenzo[a,l]pyrene in human cell lines: formation of stable DNA adducts and absence of a detectable increase in apurinic sites. (7/611)
The potent carcinogen dibenzo[a,l]pyrene (DB[a,l]P) has been reported to form both stable and depurinating DNA adducts upon activation by cytochrome P450 enzymes and/or cellular peroxidases. Only stable DB[a,l]P-DNA adducts were detected in DNA after reaction of DB[a,I]P-11,12-diol-13,14-epoxides in solution or cells in culture. To determine whether DB[a,l]P can be activated to metabolites that form depurinating adducts in cells with either high peroxidase (human leukemia HL-60 cell line) or cytochrome P450 activity (human mammary carcinoma MCF-7 cell line), cultures were treated with DB[a,l]P for 4 h, and the levels of stable adducts and apurinic (AP) sites in the DNA were determined. DNA samples from DB[a,l]P-treated HL-60 cells contained no detectable levels of either stable adducts or AP sites. MCF-7 cells exposed to 2 microM DB[a,l]P for 4 h contained 4 stable adducts per 10(6) nucleotides, but no detectable increase in AP sites. The results indicate that metabolic activation of DB[a,l]P by cytochrome P450 enzymes to diol epoxides that form stable DNA adducts, rather than one-electron oxidation catalyzed either by cytochrome P450 enzymes or peroxidases to form AP sites, is responsible for the high carcinogenic activity of DB[a,l]P. (+info)Pathologic changes induced in respiratory tract mucosa by polycyclic hydrocarbons of differing carcinogenic activity. (8/611)
Seven aromatic polycyclic hydrocarbons (PCHs) were investigated for their toxic effects on respiratory mucosa: benzo(e)pyrene (BeP), pyrene, anthracene, benz(a)anthracene(BaA), dibenz(a,c)anthracene(DBacA), benzo (a)pyrene (BaP), and dimethylbenz(a)anthracene (DMBA). The compounds were chosen because they comprise a spectrum of PCHs ranging from noncarcinogens, to initiators, to weak and strong carcinogens. All of them except DMBA are environmentally relevant chemicals. The chemicals were tested over an 8-week period. Heterotopic tracheal transplants were continously exposed and the histopathologic effects induced by the various PCHs were periodically assessed semiquantitatively. All PCHs exhibited varying degrees of toxicity for respiratory epithelium and submucosa. BeP clearly showed the least toxicity followed by pyrene and anthracene. BaA and DBacA caused marked epithelial and submucosal changes. In addition to epithelial hyperplasia, undifferentiated epithelium and squamous metaplasia developed. Marked mononuclear infiltration occurred in the subepithelial connective tissue. With BaP the epithelial and submucosal changes were similar but were much stronger. DMBA was the most toxic substance, causing epithelial necrosis followed by generalized keratinizing squamous metaplasia; the subepithelial changes consisted of an early acellular exudate and, later (at 8 weeks), marked condensation and hyalinization of the lamina propria. The toxic response pattern of the tracheal mucosa to carcinogenic agents was characterized by the chronicity of epithelial and connective tissue damage, as opposed to the short-lived hyperplastic and inflammatory response elicited by the noncarcinogens and weak initiators. (+info)
Benzopyrene
A benzopyrene is an organic compound with the formula C20H12. Structurally speaking, the colorless isomers of benzopyrene are ... Benzopyrene is a component of pitch and occurs together with other related pentacyclic aromatic species such as picene, ... Two isomeric species of benzopyrene are benzo[a]pyrene and the less common benzo[e]pyrene. They belong to the chemical class of ... Benzopyrenes are harmful because they form carcinogenic and mutagenic metabolites (such as (+)-benzo[a]pyrene-7,8-dihydrodiol-9 ...
Health effects of tobacco
The first PAH to be identified as a carcinogen in tobacco smoke was benzopyrene, which has been shown to toxicate into an ... The first PAH to be identified as a carcinogen in tobacco smoke was benzopyrene, which been shown to toxicate into a diol ... "DNA interaction with Benzopyrene". DNA. Archived from the original on December 23, 2004. Retrieved March 5, 2005. Kataoka H, ... with combustion less vaporizer technology to allow cigarettes to be consumed without the formation of carcinogenic benzopyrenes ...
Benzo(a)pyrene
Benzopyrene Benzo[e]pyrene Pyrene, a four-ring analogue Toxification Henri A. Favre, Warren H. Powell (2013). Nomenclature of ... The substance with the formula C20H12 is one of the benzopyrenes, formed by a benzene ring fused to pyrene. Its diol epoxide ... The compound is one of the benzopyrenes, formed by a benzene ring fused to pyrene, and is the result of incomplete combustion ... "Levels of Benzopyrene in Burnt toasts". Guardian Unlimited, Special reports: Close encounters. Retrieved March 5, 2005. Karle, ...
Charcoal biscuit
Food portal Activated charcoal Benzopyrene Disley, John (2006). CharcoalRemedies.com. Remnant Publications. ISBN 978-0-9738464- ...
Particulates
These soot particles also carry carcinogens like benzopyrenes adsorbed on their surface. Particulate mass is not a proper ...
Russian embargo of Ukrainian goods
29 July 2013). Kazakhstan did not find benzopyrene in the Roshen products. Ukrainian National News. (5 August 2013). Kyrgyzstan ...
Pacific Gas and Electric Company
4-benzopyrene and potassium chromate in mice drink". Arch Hyg Bakteriol. Carcinogens in water and soil. 152 (XXII): 45-53. ...
Hinkley groundwater contamination
4-benzopyrene and potassium chromate in mice drink". Arch Hyg Bakteriol. Carcinogens in water and soil. 152 (XXII): 45-53. PMID ...
Ostrava
Air quality in Ostrava is currently very poor, with high concentrations of benzopyrene. The pollution is so serious that it has ... Measurements performed by the Czech Hydrometeorological Institute show that levels of atmospheric benzopyrene and dust ...
Arene oxide
Benzopyrene is also converted to an epoxide, (+)-benzo[a]pyrene-7,8-epoxide. Benzene oxide (C6H6O) exists as an equilibrium ...
Jacques Miller
Miller, JF (1963). "Effect of thymectomy on the induction of skin tumours by 3,4-benzopyrene". Nature. 199 (4896): 920-2. ...
Epoxide
For prochiral arenes (naphthalene, toluene, benzoates, benzopyrene), the epoxides are often obtained in high enantioselectivity ...
Yeosuana
... aromativorans is a species of non-motile aerobic marine bacterium that can degrade benzopyrene. It was first isolated ...
Chernyayevsky Forest
This forms pollution of the forest park atmosphere with nitrogen dioxide, benzopyrene, formaldehyde, sulphur dioxide, soot. ...
Tobacco marketing targeting African Americans
Brown began by explaining the ingredient menthol contains compounds such as benzopyrene, which is carcinogenic when smoked. He ...
Occupational cardiovascular disease
Associations also exist for exposure to arsenic, benzopyrenes, lead, dynamite, carbon disulphide, carbon monoxide, metalworking ...
Chemical hazard
Associations also exist for exposure to arsenic, benzopyrenes, lead, dynamite, carbon disulphide, carbon monoxide, metalworking ...
Cardiovascular disease
Associations also exist for exposure to arsenic, benzopyrenes, lead, dynamite, carbon disulphide, carbon monoxide, metalworking ...
Del Amo (Superfund site)
... benzopyrene, phenanthrene and chrysene. Benzene is known to be a human carcinogen, and is detected most frequently and at the ...
Food safety incidents in Taiwan
They also tested the tainted oil for any heavy metals, aflatoxin and benzopyrene, which may cause cancer in humans. However, ...
Heterocyclic amine formation in meat
Most of the 20 HCAs are more toxic than benzopyrene, a carcinogen found in cigarette smoke and coal tar. MeIQ, IQ and 8-MeIQx ...
Ernst Wynder
Wynder also discovered specific carcinogens in tar (e.g., benzopyrenes, arsenic), but was unable to identify the contributions ...
Pyrene
Although it is not as problematic as benzopyrene, animal studies have shown pyrene is toxic to the kidneys and liver. It is now ...
Oil well fire
Smoke from burnt crude oil contains many chemicals, including sulfur dioxide, carbon monoxide, soot, benzopyrene, Poly aromatic ...
Smoker's melanosis
Smoking or the use of nicotine-containing drugs is the cause to Smoker's melanosis,. Also tar-components (benzopyrenes) are ...
FAM185A
... and benzopyrene. These interactions are not yet confirmed for the human protein, FAM185A. Currently, no diseases are known to ...
Mycobacterium vanbaalenii
3-methylcholanthrene and benzopyrene. First isolated from an environmental source, not known to be pathogenic. Strain PYR-1 = ...
Excinuclease
... damage may include thymine dimers created by UV rays as well as the bulky distortions in DNA caused by oxidized benzopyrenes ...
Hatshepsut
Her death has since been attributed to a benzopyrene carcinogenic skin lotion found in possession of the Pharaoh, which led to ...
Grilling
... benzopyrenes, and polycyclic aromatic hydrocarbons, which are carcinogens.Marination may reduce the formation of these ...
Browsing Conference of the Parties by Subject "Benzopyrenes"
Properties of Benzopyrene-DNA Complexes Investigated by Fluorescence and Triplet Flash Photolysis Techniques<...
Properties of Benzopyrene-DNA Complexes Investigated by Fluorescence and Triplet Flash Photolysis Techniques. In: Journal of ... Properties of Benzopyrene-DNA Complexes Investigated by Fluorescence and Triplet Flash Photolysis Techniques. / Geacintov, ... Geacintov NE, Khosrofian JM, Prusik T. Properties of Benzopyrene-DNA Complexes Investigated by Fluorescence and Triplet Flash ... Geacintov, N. E., Khosrofian, J. M., & Prusik, T. (1976). Properties of Benzopyrene-DNA Complexes Investigated by Fluorescence ...
Browsing 5th Session of COP (2012) by Subject
Substance Priority List | ATSDR
NIOSHTIC-2 Search Results - Full View
Benzo(a)pyrene 10353-C
Bioassay of complex mixtures derived from fossil fuels - PubMed
The conversion or processing of shale, coal, or petroleum involves elevated temperatures and altered pressures, and under these conditions polynuclear aromatic hydrocarbons are likely to form. Certain compounds of this type exhibit carcinogenic activity for a variety of organ sites in experimental a …
NIOSHTIC-2 Search Results - Full View
Publication Detail
Nanotechnology: Should carbon nanotubes be handled in the workplace like asbestos? | Blogs | CDC
Biomarkers Search
MeSH Browser
Benzopyrenes Preferred Term Term UI T004575. Date01/01/1999. LexicalTag NON. ThesaurusID NLM (1966). ... Benzopyrenes Preferred Concept UI. M0002369. Registry Number. 0. Scope Note. A class of chemicals that contain an anthracene ... Benzopyrenes [D02.455.426.559.847.799.306] * Benzo(a)pyrene [D02.455.426.559.847.799.306.300] ... Benzopyrenes. Tree Number(s). D02.455.426.559.847.799.306. D04.615.799.306. Unique ID. D001580. RDF Unique Identifier. http:// ...
PA-04-027: REDUCING PRETERM & LOW BIRTH WEIGHT IN MINORITY FAMILIES
Environmental Chemistry Class 11 Notes CBSE Chemistry Chapter 14 [PDF]
Grass-Fed Beef in City Parks -- New York Magazine - Nymag
Hexavalent chromium is carcinogenic to F344/N rats and B6C3F1 mice after chronic oral exposure - PubMed
China Says Wal-Mart Sold Food With Hazardous Levels Of Carcinogens
Liver Detoxification Phase II Support - What is it used for?
Pigment Dispersion Market Size, Share & Trends Report, 2030
trivia about drugs medicine chemicals - Trivial Trivia Collections
Shimkin, Michael 1982 - Office of NIH History and Stetten Museum
7 Cooking Vegetables Mistakes and How to Cook Vegetables Correctly | livestrong
Academic Institute - Research output
- Houston Methodist Scholars
Faris, P. M., Ritter, M. A., Abels, R. I., Ball, G. V., Bernini, P. M., Bryant, G. L., Caperton, E. M., Christoferson, L. A., De Andrade, J. R., Engh, G., Furman, W., Harmon, J. V., Hillman, R. S., Honig, S., Incavo, S., Jove, M., Landon, G. C., Nicholls, P., Savory, C. G., Sculco, T., & 2 othersSlagis, S. V. & Woodson, R., Jan 1996, In: Journal of Bone and Joint Surgery - American Volume. 78, 1, p. 62-72 11 p.. Research output: Contribution to journal › Article › peer-review ...
DeCS
MeSH Browser
Benzopyrenes Preferred Term Term UI T004575. Date01/01/1999. LexicalTag NON. ThesaurusID NLM (1966). ... Benzopyrenes Preferred Concept UI. M0002369. Registry Number. 0. Scope Note. A class of chemicals that contain an anthracene ... Benzopyrenes [D02.455.426.559.847.799.306] * Benzo(a)pyrene [D02.455.426.559.847.799.306.300] ... Benzopyrenes. Tree Number(s). D02.455.426.559.847.799.306. D04.615.799.306. Unique ID. D001580. RDF Unique Identifier. http:// ...
MH DELETED MN ADDED MN
Carcinogens3
- A preliminary study found high levels of several carcinogens, including more than eight times the acceptable soil level of benzopyrene, which is known to cause developmental problems. (nymag.com)
- This doesn't happen with vegetables, but you still don't want to burn your vegetables because other carcinogens - such as benzopyrene - can form," she explains, citing a November 2012 International Journal of Environmental Research and Public Health study. (livestrong.com)
- In the process of grilling meat, carcinogens such as benzopyrene can be created. (tekdeeps.com)
Arsenic1
- BenzoPyrene, Benzene, Arsenic and Nickel have annual concentration standards. (indiaspend.com)
Process1
- Instead of the grill, the doctor advises you to roast the food in a clean oven, without the remains of other food, to avoid the burning process and the formation of benzopyrene. (wordpress.com)
Standards1
- Wal-Mart was accused Thursday of breaching food safety standards in China by selling sesame oil containing excessive amounts of benzopyrene and squid containing hazardous levels of cadmium, both chemicals classified as carcinogenic. (ibtimes.com)
Human2
- Interactions of chrysotile and benzopyrene in a human cell culture systems. (nih.gov)
- Studies have also found that nicotine and tobacco-specific compounds (N -nitrosamines and benzopyrene) may accumulate in melanin-containing human tissues and affect melanogenesis. (medscape.com)