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PubMed1995

Desaturation and oxygenation of 1,2-dihydronaphthalene by toluene and naphthalene dioxygenase.

Bacterial strains expressing toluene and naphthalene dioxygenase were used to examine the sequence of reactions involved in the oxidation of 1,2-dihydronaphthalene. Toluene dioxygenase of Pseudomonas putida F39/D oxidizes 1,2-dihydronaphthalene to (+)-cis-(1S,2R)-dihydroxy-1,2,3,4-tetrahydronaphthalene, (+)-(1R)-hydroxy-1,2-dihydronaphthalene, and (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene. In contrast, naphthalene dioxygenase of Pseudomonas sp. strain NCIB 9816/11 oxidizes 1,2-dihydronaphthalene to the opposite enantiomer, (-)-cis-(1R,2S)-dihydroxy-1,2,3,4-tetrahydronaphthalene and the identical (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene. Recombinant Escherichia coli strains expressing the structural genes for toluene and naphthalene dioxygenases confirmed the involvement of these enzymes in the reactions catalyzed by strains F39/D and NCIB 9816/11. 1-Hydroxy-1,2-dihydronaphthalene was not formed by strains expressing naphthalene dioxygenase. These results coupled with time course studies and deuterium labelling experiments indicate that, in addition to direct dioxygenation of the olefin, both enzymes have the ability to desaturate (dehydrogenate) 1,2-dihydronaphthalene to naphthalene, which serves as a substrate for cis dihydroxylation.

Dioxygenases↗
PubMed2003

Benzene and naphthalene in air and breath as indicators of exposure to jet fuel.

AIMS: To estimate exposures to benzene and naphthalene among military personnel working with jet fuel (JP-8) and to determine whether naphthalene might serve as a surrogate for JP-8 in studies of health effects. METHODS: Benzene and naphthalene were measured in air and breath of 326 personnel in the US Air Force, who had been assigned a priori into low, moderate, and high exposure categories for JP-8. RESULTS: Median air concentrations for persons in the low, moderate, and high exposure categories were 3.1, 7.4, and 252 microg benzene/m3 air, 4.6, 9.0, and 11.4 microg benzene/m3 breath, 1.9, 10.3, and 485 microg naphthalene/m3 air, and 0.73, 0.93, and 1.83 microg naphthalene/m3 breath, respectively. In the moderate and high exposure categories, 5% and 15% of the benzene air concentrations, respectively, were above the 2002 threshold limit value (TLV) of 1.6 mg/m3. Multiple regression analyses of air and breath levels revealed prominent background sources of benzene exposure, including cigarette smoke. However, naphthalene exposure was not unduly influenced by sources other than JP-8. Among heavily exposed workers, dermal contact with JP-8 contributed to air and breath concentrations along with several physical and environmental factors. CONCLUSIONS: Personnel having regular contact with JP-8 are occasionally exposed to benzene at levels above the current TLV. Among heavily exposed workers, uptake of JP-8 components occurs via both inhalation and dermal contact. Naphthalene in air and breath can serve as useful measures of exposure to JP-8 and uptake of fuel components in the body.

Aerospace Medicine↗
PubMed1988

Haemolytic anaemia associated with ingestion of naphthalene-containing anointing oil.

We present a patient who developed a severe haemolytic anaemia as a result of ingestion of a naphthalene-containing anointing oil. Previous reports of naphthalene-induced haemolytic anaemia are reviewed. Predisposing factors to haemolysis are outlined and the variability in the haematological response to naphthalene is discussed. It is clear that ingestion of anointing oil is dangerous; even topically, significant absorption of naphthalene may occur especially in infants, as it is oil-based. Because of these dangers, the use of naphthalene-containing anointing oils should be strongly condemned.

Adult↗
PubMedDate not supplied

Naphthalene degradation and biosurfactant activity by Bacillus cereus 28BN.

Biosurfactant activity and naphthalene degradation by a new strain identified as Bacillus cereus 28BN were studied. The strain grew well and produced effective biosurfactants in the presence of n-alkanes, naphthalene, crude oil and vegetable oils. The biosurfactants were detected by the surface tension lowering of the medium, thin layer chromatography and infrared spectra analysis. With (2%) naphthalene as the sole carbon source, high levels of rhamnolipids at a concentration of 2.3 g 1(-1) were determined in the stationary growth. After 20 d of incubation 72 +/- 4% of the initial naphthalene was degraded. This is the first report for a Bacillus cereus rhamnolipid producing strain that utilized naphthalene under aerobic conditions. The strain looks promising for application in environmental technologies.

Bacillus cereus↗
PubMed1979

Glutathione and mercapturic acid conjugations in the metabolism of naphthalene and 1-naphthyl N-methylcarbamate (carbaryl).

The formation of glutathione (GSH) conjugate in the detoxification of [1-14C]-naphthalene and [naphthyl-14C]-carbaryl was investigated using rat liver homogenate. The mercapturic acid conjugate in rats was also investigated by collection of urine after intraperitoneal injection of 14C substrates. The formation of water-soluble metabolites in vitro from naphthalene was dependent on the amount of glutathione added, but this was not seen in carbaryl metabolism. In vitro, the metabolism of [1-14C]-naphthalene produced 50% GSH conjugates in the incubation mixture, whereas in vivo the metabolism of this compound produced 65% mercapturic acid conjugate in the urine. There was no evidence of GSH or mercapturic acid conjugate in the metabolism of [naphthyl-14C]-carbaryl in vitro and in vivo. This conclusion was made by comparing the nature and chemical characteristics of GSH and mercapturic acid conjugates formed in [1-14C]-naphthalene metabolism. With the aid of the specific enzyme (e.g. beta-glucuronidase and sulfatase) and acid hydrolysis, the water-soluble metabolites of [naphthyl-14C]-carbaryl were tentatively recognized as glucuronide or sulfate conjugated mainly with 5,6-dihydro-5,6-dihydroxycarbaryl or N-hydroxy-methyl carbaryl and their hydrolytic products. This data demonstrated that the substituent group on the naphthalene molecule may affect the significance of GSH conjugation.

Acetylcysteine↗
PubMed1990

Glutathione synthesis and glutathione redox pathways in naphthalene cataract of the rat.

This investigation examined many parameters during the course of early development of naphthalene-induced cataract in a time span of 0 to 79 days of treatment. Feeding naphthalene daily to Black-Hooded rats resulted in gradual progressive development of cataract. The first faint opacities were detectable after 7 days. Free soluble total glutathione (oxidized and reduced) of these lenses was shown to gradually decrease to a maximum loss of about 20%, a value reached by day 30 of treatment. No activity loss of either enzyme required for glutathione synthesis (gamma-glutamylcysteine synthetase or glutathione synthetase) was observed in homogenates of naphthalene versus control lenses. There was also neither impairment of [35S]-L-cystine uptake nor of [35S]-glutathione synthetic capacity in lenses cultured from rats after 12, 24 or 36 days of naphthalene feeding when compared to control lenses. Hence, glutathione loss cannot be explained by a damaged glutathione synthesis system. Progressive activity loss of glutathione peroxidase and glutathione reductase was observed. The loss of glutathione peroxidase activity was especially remarkable. Thus, the defense system against oxidative damage is impaired and may be a significant factor in naphthalene-induced cataract of the rat.

Animals↗
PubMed1998

Mass transfer effects on microbial uptake of naphthalene from complex NAPLs.

The bioavailability of naphthalene present as a component of a complex nonaqueous phase liquid (NAPL) comprised by nine aromatic compounds was investigated. Specifically, the effects of naphthalene mass transfer from the NAPL to the aqueous phase on rates of its microbial degradation were examined. The investigations were conducted using a pure culture, ATCC 17484, and a mixed culture of naphthalene-degrading bacteria, the former having been implicated previously in the direct uptake of sorbed naphthalene. The studies were conducted in mass-transfer-limited, segregated-phase reactors (SPRs) in which both the NAPL and aqueous phases were internally well-mixed. A 30-day active biodegradation period was preceded and followed by a 5-7-day period devoid of bioactivity, during which time the rates and extents of mass transfer of components from the NAPL to the aqueous phase were quantified. The NAPL-phase naphthalene mass depletion profiles during biodegradation were compared to those predicted by assuming maximum mass depletion under mass-transfer-limited conditions using both pre- and post-biodegradation dissolution rate and equilibrium parameters. The observed mass depletion rates were high during the initial stages of biodegradation but decreased significantly in later stages. Throughout biodegradation, even in the initial rapid stage, mass depletion rates never exceeded maximum predicted rates based on pre-biodegradation mass transfer parameters. Reduced depletion rates in the later stages appear to relate to mass transfer hindrance caused by formation of biofilms at the NAPL-water interface.

Bacteria↗
PubMedDate not supplied

[Degradation of phenanthrene by mutant strains--naphthalene degraders].

Five naphthalene- and salicylate-utilizing Pseudomonas putida strains cultivated for a long time on phenanthrene produced mutants capable of growing on this substrate and 1-hydroxy-2-naphthoate as the sole sources of carbon and energy. The mutants catabolize phenanthrene with the formation of 1-hydroxy-2-naphthoate, 2-hydroxy-1-naphthoate, salicylate, and catechol. The latter products are further metabolized by the meta- and ortho-cleavage pathways. In all five mutants, naphthalene and phenanthrene are utilized with the involvement of plasmid-borne genes. The acquired ability of naphthalene-degrading strains to grow on phenanthrene is explained by the fact that the inducible character of the synthesis of naphthalene dioxygenase, the key enzyme of naphthalene and phenanthrene degradation, becomes constitutive.

Biodegradation, Environmental↗
PubMed2001

Mass transfer effects on microbial uptake of naphthalene from complex NAPLs.

The bioavailability of naphthalene present as a component of a complex nonaqueous phase liquid(NAPL) comprised by nine aromatic compounds was investigated. Specifically, the effects of naphthalene mass transfer from the NAPL to the aqueous phase on rates of its microbial degradation were examined. The investigations were conducted using a pure culture, ATCC 17484, and a mixed culture of naphthalene-degrading bacteria, the former having been implicated previously in the direct uptake of sorbed naphthalene. The studies were conducted in mass-transfer-limited, segregated-phase reactors(SPRs) in which both the NAPL and aqueous phases were internally well-mixed. A 30-day active biodegradation period was preceded and followed by a 5-7-day period devoid of bioactivity, during which time the rates and extents of mass transfer of components from the NAPL to the aqueous phase were quantified. The NAPL-phase naphthalene mass depletion profiles during biodegradation were compared to those predicted by assuming maximum mass depletion under mass-transfer-limited conditions using both pre- and post-biodegradation dissolution rate and equilibrium parameters. The observed mass depletion rates were high during the initial stages of biodegradation but decreased significantly in later stages. Throughout biodegradation, even in the initial rapid stage, mass depletion rates never exceeded maximum predicted rates based on pre-biodegradation mass transfer parameters. Reduced depletion rates in the later stages appear to relate to mass transfer hindrance caused by formation of biofilms at the NAPL-water interface.

Bacteria↗
PubMedDate not supplied

[Bacterial chemotaxis to naphthalene].

The chemotaxis of two pseudomonads, P. putida AZ (Naph+) and P. putida AZ (Naph-), differing in the ability to metabolize naphthalene was studied by the known capillary method of Adler and the densitometric method devised in our laboratory. The migration of P. putida AZ (Naph+) cells toward increasing levels of naphthalene was accompanied by the formation of a migrating front of converted naphthalene. P. putida AZ (Naph-) cells, too, exhibited positive chemotaxis to naphthalene, but they did not form the front of converted naphthalene. The analysis of experimental data in terms of a kinetic model of bacterial chemotaxis showed that the densitometric method is a potential tool for studying bacterial chemotaxis to hydrophobic organic substances.

Chemotaxis↗
PubMed1992

Relationship of cytochrome P-450 activity to Clara cell cytotoxicity. I. Histopathologic comparison of the respiratory tract of mice, rats and hamsters after parenteral administration of naphthalene.

The purpose of this study was to define the sites of cytotoxicity within the respiratory tract (nasal cavity and tracheobronchial airway tree) resulting from administration of naphthalene, an organic chemical whose cytotoxic properties require metabolic activation via the cytochrome P-450 monooxygenase system. Three species were compared: mouse, hamster and rat. Naphthalene was administered in corn oil at these doses: mouse (0-400 mg/kg), hamster (0-800 mg/kg) and rat (0-1600 mg/kg), and the animals were sacrificed 24 hr later. In mice, naphthalene produced Clara cell cytotoxicity at 50 mg/kg. The primary alteration was swelling and vacuolation of Clara cells in terminal bronchioles. At 100 mg/kg, the number of terminal bronchioles with vacuolated Clara cells and the number of Clara cells within terminal bronchioles which showed vacuolation increased. At 200 and 300 mg/kg, almost all of the nonciliated cells lining terminal bronchioles in mice were exfoliated and necrotic. In contrast, there was no apparent effect on Clara cells or ciliated cells of terminal bronchioles in rats treated with up to 1600 mg/kg. At 800 mg/kg, minor alterations in Clara cells in some terminal bronchioles were observed in hamsters. At 300 mg/kg, lobar bronchus and trachea showed swelling 'and vacuolation of nonciliated cells in mice, but no detectable change at 200 mg/kg or below. The trachea and lobar bronchus were unaffected in rats, but showed cytotoxic changes in hamsters. In the nasal cavity of mice, cytotoxicity was observed only in the olfactory epithelium and only in animals treated with 400 mg/kg. There were minimal alterations in the respiratory epithelium. The only epithelial population showing cytotoxicity in the rat was the olfactory epithelium. Complete necrosis was observed at 200 mg/kg and higher. In the hamster there was no discernible alteration in the olfactory epithelium at 100 and 200 mg/kg. At 400 mg/kg, the olfactory epithelium was necrotic. Naphthalene injury to the tracheobronchial epithelium of the mouse is: 1) Clara cell specific; 2) dose-related in the terminal bronchiole; and 3) involves more proximal airways in a dose-dependent fashion. The tracheobronchial epithelium of the rat is refractory to Clara cell injury even at the LD50, but proximal airways are more susceptible than distal airways in the hamster. The nasal cavity shows specific injury in one zone (olfactory epithelium) in a dose and species specific manner. The susceptibility to naphthalene-induced injury in the olfactory epithelium does not correlate with the susceptibility of Clara cells in more distal portions of the respiratory tract.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMedDate not supplied

[Diversity of genetic systems responsible for biodegradation of naphthalene in Pseudomonas fluorescens strains].

The genetic systems that are responsible for naphthalene catabolism were analyzed in 18 naphthalene-degrading Pseudomonas fluorescens strains isolated from oil-contaminated soils in different regions of Russia. It was found that thirteen strains contain plasmids, from 20 to 120 kb in size, at least five of which are conjugative and bear the catabolic genes responsible for the complete utilization of naphthalene and salicylate. Five plasmids belong to the P-7 incompatibility group, and two plasmids belong to the P-9 incompatibility group. The naphthalene biodegradation genes of P. fluorescens are highly homologous to each other. The study revealed a new group of the nahAc genes and two new variants of the nahG gene. The suggestion is made that the key genes of naphthalene biodegradation, nahAc and nahG, evolve independently and occur in P. fluorescens strains in different combinations.

Cluster Analysis↗
PubMed2006

[Adsorption of toluene and naphthalene on Beijing soils and its influence factor].

Static adsorption experiments were carried out to investigate the adsorption of toluene and naphthalene on Beijing soils, and to determine the influence of temperature and surfactants on adsorption. Although the affinity of petroleum hydrocarbons for seven soils is different, the adsorption isotherms of toluene and naphthalene on seven soils are well described by the Freundlich type. The adsorbed amount of naphthalene is higher than that of toluene on the same soil. High temperature doesn't benefit adsorption. Cetylrimethyl ammonium bromide (CTAB) and sodium dodecyl benzene sulfonate (SDBS) both have a positive effect on desorption of toluene and naphtalaene from soil. The desorption rate of toluene and naphthalene in the presence of CTAB and SDBS is 27.5%, 12.1% and 64.3%, 48.8%, respectively, which show that SDBS plays a much more important role in desorption than CTAB. The adsorbed quantities of toluene and naphthalene decrease with increasing SDBS concentration. When CTAB concentration is lower than the critical micelle concentration (CMC), adsorption increases with increasing CTAB concentration; When CTAB concentration is equal to or higher than CMC, adsorption decreases with increasing CTAB concentration.

Adsorption↗
PubMedDate not supplied

Isozymes of cytochrome P-450 that metabolize naphthalene in liver and lung of untreated mice.

Four isozymes, designated P-450m50a, P-450m50b, P-450m51a, and P-450m51b, have been isolated from liver microsomes of untreated male CD-1 mice. Electrophoretograms revealed that the molecular weights of P-450m51a and P-450m51b were about 51,000, whereas those of P-450m50a and P-450m50b were about 49,700 and 49,500, respectively. The present study is concerned mainly with the elucidation of the characteristics of P-450m50b and P-450m51a, since they appear to be major forms of cytochrome P-450 in mouse liver. End group analyses have revealed that these forms differ not only from P1-450, isolated previously from mouse liver, but also from any other known isozymes of cytochrome P-450. Naphthalene was metabolized by both P-450m50b and P-450m51a, but the turnover number of P-450m50b was 2-4 times greater than that of P-450m51a. Moreover, P-450m50b formed predominantly (1R,2S)-naphthalene 1,2-oxide, as determined by the formation of trans-1(R)-hydroxy-2(R)-glutathionyl-1,2-dihydronaphthalene, whereas P-450m51a formed both (1R,2S)- and (1S,2R)-naphthalene 1,2-oxide in about equal amounts. Although cytochrome P-450c, isolated from rat liver, is also known to convert naphthalene predominantly to (1R,2S)-naphthalene 1,-2-oxide, an antibody prepared against cytochrome P-450c failed to inhibit the formation of the glutathione conjugate when the 1R,2S-oxide was formed by either pure P-450m50b or by microsomes from mouse lung. Thus, P-450m50b probably is not orthologous to cytochrome P-450c.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1990

Metabolic activation and bronchiolar Clara cell necrosis from naphthalene in the isolated perfused mouse lung.

A method for isolation and maintenance of the mouse lung ex vivo suitable for the study of the relationship between metabolism and toxicity is described. Physical, biochemical and morphological evaluations revealed that the lung is viable for up to 5 hr. No significant alterations in the architecture of the bronchiolar epithelium were observed by light or electron microscopy, despite evidence of interstitial and peribronchial edema. Although increases in pulmonary arterial pressure were noted at 5 hr, lung wet/dry weight was elevated only minimally (11%). Glutathione levels remained stable for the first 3 hr but fell to 57 +/- 14% of control at 5 hr. Naphthalene monooxygenase activity was not altered significantly during 5 hr of perfusion. Perfusion of the lung with naphthalene resulted in swelling and vacuolation of Clara cells followed by concentration-dependent losses of this cell type from the bronchiolar epithelium. Clara cells comprised 63% of the epithelial cells in terminal airways of control mice; 10 mumol of naphthalene decreased this number to 30%. Perfusion with naphthalene resulted in concentration-dependent decreases in pulmonary glutathione. Reactive metabolites were bound covalently to protein in the lung and in the perfusate. This study is the first to provide unambiguous evidence that naphthalene-induced Clara cell necrosis can be mediated entirely by processes resident in the lung. In addition, this work validates the use of the isolated perfused mouse lung for studying the role of reactive metabolites produced in situ vs. those entering the lung via the circulation.

Animals↗
PubMedDate not supplied

Epoxide intermediates in the metabolism of naphthalene by the rat.

Twenty-one oxygenated metabolites of naphthalene have been isolated from rat urine and characterized by gas chromatography and gas chromatography and gas chromatography-mass spectrometry. Studied with naphthalene-1,4-d2 confirmed that the compounds characterized by GC/MS were derived from naphthalene. The structures of a number of metabolites were confirmed by synthesis. All but one of these metabolites were formed by processes involving epoxidation, and the structures of the metabolites support the hypothesis that multiple epoxides and a cyclic peroxide are involved in the in vivo metabolism of naphthalene by the rat. The evidence provided by this and our previous studied indicates that the anti-diepoxide of naphthalene is a mammalian metabolite. Ten methylthio metabolites were isolated in earlier studies. Excluding mercapturic acids, conjugates, and related compounds, the total number of isolated compounds is now 31, and several additional compounds must have been present as intermediates. The structures of epoxide intermediates are indicated by precursor-product relationships.

Animals↗
PubMedDate not supplied

[Lipid peroxidation in blood plasma of experimental animals treated with naphthalene oil].

40 rabbits were used in the experiments, where 10 animals were in control group, and 3 groups of the animals were treated with naphthalene oil obtained from various pit-holes NN 39, 54 and 88. The treatment course included 10 applications of naphthalene oil, which was placed on lateral body surface, 10 x 10 cm, a dose of 1.0 ml/kg, within 10 min. A state of lipid peroxidation was evaluated by measurement of hydroperoxides, diene conjugates and malonic dialdehyde in rabbit blood. Some decrease in content of lipoperoxides was observed in rabbits after the course of naphthalene oil treatment and the oil from the pit-hole 54 exhibited the highest effect. These results may be involved in evaluation of the naphthalene oil medicinal effects as well as in working out recommendations to use the naphthalene oil not from usual reservoir, but namely from pit-hole 54 for treatment of patients with impaired lipid metabolism.

Animals↗
PubMed1996

Prevention of acetaminophen- and naphthalene-induced cataract and glutathione loss by CySSME.

PURPOSES: To assess the efficacy of 2-mercaptoethanol/L-cysteine mixed disulfide (CySSME) as an L-cysteine prodrug suitable for glutathione biosynthesis in rat lenses in vitro, as an agent for the prevention of acetaminophen- and naphthalene-induced murine cataract in genetically-susceptible mice, and as an agent for maintenance of near-normal glutathione levels in lenses and livers of mice subjected to acetaminophen and naphthalene at cataractogenic doses. METHODS: Synthetic CySSME was added as a prodrug to rat lens culture medium devoid of L-cystine and L-methionine but containing [14C(U)]-glycine. After a 48-hour period of incubation, extracts of rat lenses were prepared for separation of [14C]-glutathione by high-performance liquid chromatography (HPLC) with a radioisotope detector to determine the extent of its biosynthesis. Cytochrome P-450 isozymes were induced in C57 bl/6 mice by either beta-naphthoflavone or phenobarbital. Cataracts were induced by administration of either acetaminophen or naphthalene to the pretreated mice. CySSME was coadministered with either acetaminophen or naphthalene to other groups of mice. Both oxidized and reduced glutathione were determined in extracts of livers and lenses using the HPLC method above. RESULTS: CySSME served as an effective L-cysteine precursor for glutathione biosynthesis in cultured rat lenses. This L-Cysteine prodrug was also highly effective in preventing acetaminophen- and naphthalene-induced cataract in mice and in maintaining near-normal glutathione levels in lenses and livers of such treated animals. CONCLUSIONS: This investigation demonstrates that maintenance of adequate physiological levels of glutathione in the presence of specific known cataractogenic agents by pharmacologic intervention with CySSME, an L-cysteine prodrug, is sufficient to prevent cataract formation.

Acetaminophen↗