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Synchrotron radiation was used for determining single‐photon photoconductivity thresholds for various solutes in nonpolar solvents. For anthracene as a solute the thresholds (Eth) are 6.14, 6.07, and 5.87 eV in 2,2,4‐trimethylpentane, 2,2,4,4‐tetramethylpentane, and tetramethylsilane, respectively. The threshold decreases as the conduction band energy (V0) decreases. The polarization energy (P+) of the anthracene cation, as derived from the data for 2,2,4‐trimethylpentane, is one‐third larger in magnitude than that reported for the polarization energy of the anthracene anion in this solvent, which suggests that the cation is smaller than the anion. Thresholds were also measured for 1,2‐benzanthracene, azulene, perylene, triphenylamine, and diazabicyclo‐octane. The thresholds in solution and solvation terms are related quantitatively by the expression Eth=I.P.+V0+P+.

We have examined the relationship between topical psoriasis treatment and the activity of the mixed function oxidase, aryl hydrocarbon hydroxylase (AHH), in peripheral blood monocytes and lymphocytes from 20 patients with psoriasis. These data were compared to monocyte and lymphocyte AHH activity measured in 20 normal subjects. AHH activity was determined in cells induced with benzanthracene and in uninduced control cells. Monocyte and lymphocyte AHH activity in six untreated psoriasis patients was similar to that in the healthy controls. AHH activity in either uninduced or induced monocytes showed an increase with age in both the healthy and the untreated psoriatic subjects. Lymphocytes from the healthy subjects showed an age-related decline in enzyme activity. Fourteen patients with psoriasis receiving topical tar and/or topical corticosteroid therapy had significantly higher (P less than 0.05) levels of basal and induced monocyte and lymphocyte AHH activity than the healthy controls. AHH activity is age-related and appears to be controlled differently in monocytes and in lymphocytes. AHH activity in circulating monocytes and lymphocytes may be stimulated by topical tar and/or steroid therapy of psoriasis.

We have demonstrated the utility of an Escherichia coli microsuspension assay to detect and characterize chemical mediation of DNA damage by a wide variety of mutagens and carcinogens. The assay have been improved by the development of a microsuspension modification to the Bacillus subtilis ''rec'' assay. The addition of these gram-positive organisms has allowed detection of DNA damage induced by benzo(a)pyrene (B(a)P), 3-aminopyrene (3-AP), 7, 12-dimethylbenz(a)anthrancene (DMBA), 3-methylcholanthrene (3-MC), and 4-nitrobiphenyl (4-NBP). Data presented in this paper from tests of 61 additional compounds, including a representative number of direct and promutagenic agents, indicate that the B subtilis H17 and M45 strains provide an effective microbial system for identification of DNA damage susceptible to postreplicational repair. The results of this study further suggests that the inclusion of these strains in the microsuspension assay for DNA damage will markedly enhance the detection of agents which cannot readily penetrate the intact cell wall of E coli.

The Thermaikos Gulf area is suspected of being contaminated with petroleum hydrocarbons. A total of 57 samples were analyzed as follows: 29 from the western area (industrial) and 28 from the eastern area (agricultural) of the Gulf. All samples examined were found to be contaminated. The levels detected ranged from trace to 13 ng/g (wet weight, drained). Seven of the samples examined contained benzo(a)pyrene at an average level of 1 ng/g. Dibenzo(a,i)pyrene was found at trace levels in a small proportion of samples. Another compound, benzo(a)anthracene, was found in 19 samples at concentrations ranging from 2 ng/g to 42 ng/g. Dibenzo(a,h)pyrene was not found in any of the samples analyzed. On the basis of the above data, the concentration of total PAH in mussels of the Thermaikos Gulf amounted to 91 ng/g (wet weight) and those of the carcinogenic PAH counted to 19 ng/g. (JMT)

A 32P-adduct assay for the measurement of low levels (1 adduct per 10(7) nucleotides) of binding of carcinogens to DNA has been reported previously. In this procedure, DNA is enzymatically hydrolyzed to 3'-monophosphates of normal nucleosides and adducts, which are 5'-32P-labeled by T4 polynucleotide kinase and [gamma-32P]ATP. Labeled adducts are resolved by TLC. Enrichment of adducts by extraction in 1-butanol [Gupta, R.C. (1985) Cancer Res., 45, 5656] or digestion with nuclease P1 [Reddy, M.V. and Randerath, K. (1986) Carcinogenesis, 7, 1543] prior to 32P-labeling, however, increased the sensitivity of detection for many adducts to a level of 1 per 10(9-10) nucleotides, although adduct recovery particularly in the latter assay depended on the chemical nature of adducts. We have now compared recoveries for greater than 70, different carcinogen-DNA adducts of known and unknown chemical nature in the two enrichment procedures as well as in a new procedure in which polynucleotide kinase is substituted for nuclease P1. When compared with the butanol extraction procedure, arylamines (such as 2-aminofluorene, 2-aminophenanthrene, 2-naphthylamine, 4-aminobiphenyl, 4-azoaminobenzene and N'-acetylbenzidine) bound to the C8 position of guanine were lost almost completely (0.2-4% recovery) in the nuclease P1-mediated assay, but the presence of a polar group in the aromatic amine moiety (such as 2-acetylaminofluorene, 2-acetylamino-phenanthrene and methyl-4-azoaminophenyl) rendered similar recovery. In contrast, aromatic amines (2-amino-phenanthrene, 2-acetylaminophenanthrene, 2-acetylaminofluorene and methyl-4-azoaminobenzene) and polycyclic aromatic hydrocarbons (benzo[a]pyrene, bromomethylbenzanthracene and benzanthracene) bound to the exocyclic positions of guanine or adenine showed extensive or as complete recovery in the nuclease P1 procedure as in the extraction procedure. Some of the unknown presumably polar adducts showed a lower recovery (30-70%) in the butanol procedure as compared to the nuclease P1 enrichment. The recovery pattern of most adducts examined in the polynucleotide kinase-enrichment assay was essentially the same as found in nuclease P1-mediated assay, except that overall lower values were obtained. Our data suggest that a given DNA sample should be analyzed by different versions of the 32P-adduct assay, particularly, DNA of specimens of humans exposed to low levels of unknown carcinogens. The observation that chemical structure of an adduct may be detrimental in its recovery in the enzyme- and extraction-mediated enrichment procedures may serve as a probe in the structural characterization of adducts of unknown carcinogens.

A component capable of binding benzo(a)pyrene was measured in plasma from cigarette smokers and nonsmokers. This plasma fraction was found to have a high specificity of binding to benzo(a)pyrene, bound benzanthracene competitively with benzo(a)pyrene, and was positively correlated (r = 0.861, p less than 0.001) with the capacity of the individual subject's lymphocytes to be induced for AHH activity in culture. An inverse correlation (r = -0.957, p less than 0.001) between the presence of the plasma component in lung cancer patients and the capacity of lung cancer patients' lymphocytes to be induced in culture is unexplained at this time. A benzo(a)pyrene-binding fraction was not found in induced or uninduced cultured lymphocytes from smokers or nonsmokers, or in homogenates of lung excisional tissue from smokers with or without primary lung cancer.

Carbon-13 chemical shifts are reported for a series of carcinogenically active and related inactive polynuclear hydrocarbons. Resonance assignments for complex systems such as 3-methylcholanthrene, dibenzanthracenes, benz[a]anthracene and its 7-methyl and 7,12-dimethyl derivative, have been made primarily from a study of simpler models, including phenanthrene, triphenylene, and anthracene. Selective proton decoupling has been employed extensively. Quaternary carbon assignments have been aided by deuterium isotope shift and spin–lattice relaxation time measurements. Vicinal C—D couplings have been found to be unreliable as means of assignment for quaternary carbons.

We studied the fine structure of benign, premalignant and malignant melanocytic lesions induced in Dunkin-Hartley guinea pigs by means of topical application of 7,12-dimethyl-benzanthracene (DMBA). The most noteworthy characteristics of the atypical melanocytes (melanocytic dysplasia and melanomas) were the variable morphology and structure, and, in particular, the aberrant character of the melanosomes. The melanocytes presented irregularity of nuclear outlines with frequent lobulation. The heterochromatin was usually found in thick clumps reinforcing the nuclear membrane, and the nucleoli were usually multiple. The melanosomes were ellipsoidal and spherical with a pattern that was lamellar, concentric, incomplete, and even microgranular and microvesicular. The melanization was usually in thick, irregular clumps. Melanosome complexes were always present.

Metabolism of 15,16-dihydro-11-methylcyclopenta[a]phenanthren-17-one with hamster embryo cells and a human hepatoma cell line HepG2 is compared. Essentially, no metabolism was seen with hamster embryo cells but with the HepG2 cells, especially after induction with benzanthracene or Arochlor, this carcinogenic ketone was metabolized to give 1,2-dihydroxy-11-methyl-1,2,15, 16-tetrahydrocyclopenta[a]phenanthren-17-one, 3,4-dihydroxy-11-methyl-3,4,15,16-tetrahydrocyclopenta[a] phenanthren-17-one, 15,16-dihydro-15-hydroxy-11-methylcyclopenta[a]phenanthren-17-one, 15,16,-dihydro-16-hydroxy-11-methylcyclopenta[a]phenanthren-17- one, and three new metabolites, 16,17-dihydro-11-methyl-4,15,17-trihydroxy-15H-cyclopenta[a]phe phenanthrene, 15,16-dihydro-16,17-dihydroxy-11-methylcyclopenta[a]phenanthrene and 16,17-dihydro-11-methyl-15H-cyclopenta[a]phenanthren-17-ol. The reduction of the 17-ketone group and the formation of phenols with HepG2 cells appears to be the major difference between metabolism of 15,16-dihydro-11-methylcyclopenta[a]phenanthren-17-one with HepG2 cells and rat liver microsomes. The metabolic products of this ketone also bind to DNA. These results suggest that the component of the aryl hydrocarbon hydroxylase enzyme system that is responsible for the activation of cyclopenta[a]phenanthrenes is specific and not the same as that needed for polycyclic aromatic hydrocarbons, and that HepG2 cells contain a reductase which is specific for the 17-ketone function in the cyclopenta[a]phenanthrenes.

Diels-Alder reaction of 1,3-dimethylisobenzofuran with cinnamic esters allows for the synthesis of a variety of 7,12 dimethylbenzanthracene derivatives. The sterically congested 1,7,12 trimethylbanzanthracene was prepared.

Fur Benzoldiazonium-tetrafluoroborat und eine Anzahl p-substituierter Derivate werden ermittelt: Geschwindigkeitskonstanten der photochemischen Elektronenubertragung von Pyren bzw. Benzanthracen auf das Diazoniumsalz in Acetonitril (Bestimmung durch Loschung der Fluoreszenz des Elektronendonors); Geschwindigkeitskonstanten der Elektronenanlagerung unter den Bedingungen der Pulsradiolyse in tert-Butanol/Wasser; Quantenausbeuten und Produktzusammensetzung (ArOMe, ArF bzw. ArH) bei der Photolyse in Methanol in Gegenwart verschiedener Konzentrationen an 2-Methyl-2-nitrosopropan zur Inhibierung der nachfolgenden thermischen Kettenreaktion. Die Elektronenubertragung bzw. -Anlagerung ist diffusionskontrolliert, kE = 2 …; 3 × 1010 l/mol · s. Fur den Gesamtverlauf wird ein kinetisches Modell aufgestellt, mit dessen Hilfe aus den Mesdaten absolute Geschwindigkeitskonstanten fur folgende Teilreaktionen erhaltlich sind: H-Ubertragung innerhalb des Kafig-Radikalpaares (Bildung von ArH), kH ≈ 1011 s−1; Maximalwerte fur die Photosolvolyse (Bildung von Ar⊕ ArOMe bzw. ArF), ks ≲ 1011 s−1; Abfang der Arylradikale auserhalb des Losungsmittelkafigs durch t-BuNO, kq ≈ 2 × 107 l/mol· s. Die Ergebnisse werden im Zusammenhang mit dem aufgestellten kinetischen Modell und weiteren Befunden diskutiert. Kinetics and Mechanism of Aryldiazonium Salt Photolysis in Methanol. Determination of Absolute Rate Constants of Some Reaction Steps For benzene diazonium tetrafluoroborate and some p-substituted derivatives, the following values are determined: velocity constants for the photochemical electron transfer from pyrene and benzanthracene to aryl diazonium salts in acetonitrile solution (determination by quenching the donor fluorescence). velocity constants for electron transfer under the condition of pulse radiolysis in tert.-butanol-water solution; quantum yields and product composition (ArOMe, ArF and ArH, respectively) for the photolyses in methanol in the presence of varying concentrations of 2-methyl-2-nitroso-propane as a quencher of the thermal chain reaction. The electron transfer reaction comes out be a diffusion controlled reaction, kE = 2 … 3 × 1010 M−1 s−1. For the total reaction a kinetic model is set up which affords absolute velocity constants from the experimental results for the following steps: Hydrogen transfer within the case radical pair (formation of ArH) kH ≈ 1011 s−1; Maximal values for the photo-solvolyses (formation of Ar⊕ ArOMe and ArF, respectively), ks ≲ 10−1; Trapping of aryl radicals outside of the solvent cage by t-BuNO, kq ≈ 2 × 107 M−1 s−1. The results are discussed in the light of the kinetic model and some other facts.

Polymers were prepared from 4,4′-diphenoxydiphenylsulfone, isophthaloyl dichloride, and bis-p-phenoxyphenyl-4,4′-(2,2′-dibromodiphenyl)ketone, 2,2′-dibromodiphenyl-4,4′-dicarbonyl dichloride, or bis-p-phenoxyphenyl-4,4′-(2,2′-diphenylethynyldiphenyl)ketone in Friedel-Crafts type of polymerization. Bromine groups were subsequently replaced with phenylacetylene residues, and the polymers were cured at high temperatures, with the apparent formation of benzanthracene linkages. Cured polymers exhibited higher softening points, decreased solubilities, and, in some instances, higher melting points than their uncured precursors. Significant weight losses occurred during isothermal aging tests.

A method is described for the determination of triplet annihilation parameters with a “triplet” spectrophotometer where absorption and emission data, spectral as well as time resolved, are obtained from the same sample under identical conditions. Of particular interest is the determination of the probability for delayed production of an excited singlet molecule from the encounter of two triplets and the mean interaction radius in the diffusion controlled annihilation mechanism.

A device capable of collecting simultaneously eight equivalent particulate diesel exhaust samples was constructed to test the effect of filter type, extraction solvent and storage condition on the measured concentration of five PAH compounds (fluoranthene-Ft, pyrene-Py, benz(a)anthracene-BaA, benzo(k)fluoranthene-BkFT, and benzo(a)pyrene-BaP) in diesel exhaust. An experimental design was used to most efficiently test the variables. A linear model (GLM) was used to analyze the data.

The Aurelia Metamorphosis Test System was devised to use simple Aurelia polyps as indicator organisms for the detection of subtle effects of petroleum-related hydrocarbons and of Alaskan crude petroleum oil (ACPO) on developmental processes involved in strobilation initiation, differentiation of ephyrae, and genetic modification expressed through cloning. Compounds tested were ACPO, aniline, anthracene, benzanthracene, benzene, benzo[a]pyrene, biphenyl, cresol, naphthalene, perylene, phenol and pyrene. Gross morphology of the ephyrae (patterning, numbers and appearance of structures), statolith and mematocyst numbers, and pulsing behavior were recorded using the light microscope. Selected ephyrae with teratological malformations were studied with the scanning electron microscope and swimming behavior was observed visually. The variety of subtle developmental, behavioral and genetic effects due to marine hydrocarbons detected using the Aurelia Metamorphosis Test System demonstrated that this test system could be used as an early warning system to detect subtle effects of other marine pollutants.

Linear dichroism UV spectroscopy on samples aligned in stretched polymer sheets or liquid crystals provides useful information on transition moments. This can be combined with results from fluorescence polarization and linear dichroism IR spectroscopy to give very precise values for the UV transition moment directions in molecules of low symmetry.

The ingestion of 14C-labeled 9,10-dimethyl-1,2-benzanthracene particles, the extracellular release of acid phosphatase, ribonuclease, and α-glucosidase, and the egestion of preingested dimethylbenzanthracene particles by Tetrahymena taken from logarithmically growing cultures and resuspended in a dilute salt solution were followed in the presence of several pharmacologic agents. Serotonin, caffeine, and, to a lesser extent, dibutyryl cyclic AMP increased the rate of particle ingestion, but did not alter the rate of release of the three acid hydrolases studied. Added catecholamines did not affect either particle ingestion or acid hydrolase release, but particle ingestion was inhibited by the catecholamine antagonists, dichloroisoproterenol, desmethylimipramine, reserpine, and phenoxybenzamine. These drugs also increased the release of acid phosphatase and ribonuclease in 5-h incubations. Desmethylimipramine acted within 1 h to increase acid hydrolase release, but the effect of dichloroisoproterenol developed more slowly and was secondary to a change in cellular content of the hydrolases. Desmethylimipramine increased the energy of activation for the release of acid phosphatase, while dichloroisoproterenol did not. Both of these drugs enhanced the egestion of preingested dimethylbenzanthracene particles, supporting the view that acid hydrolase release occurs through a cytoproct egestion mechanism. Particle ingestion was also inhibited by colchicine, vinblastine, and cytochalasin B, but these agents had no effect on acid hydrolase release, thus further differentiating the properties of the ingestion mechanism from those of the egestion mechanism. It appears that both microtubules and microfilaments play a role in the ingestion process and that this process may be controlled in part by a cyclic AMP-mediated serotoninergic and adrenergic system.

S 1 → S 0 internal conversion ( k IC ) and S 1 → T 1 ( k ISC ) intersystem crossing rate constants were determined and compared in the group of mono- and di-aza derivatives of 1,2-benzanthracene. Quantum yields of triplet formation (Φ ISC ) were obtained from pulsed photoacoustic measurements. The extremely fast k ISC = 4 × 10 10 s −1 was found for 1,2-benzphenazine in aprotic solvents. k IC of free bases and monoprotonated species are two orders of magnitude greater than that of the parent hydrocarbon.

The cytochrome P-450 component of the mixed function oxidase in rat liver microsomes is modified to a species with a reduced CO complex spectral peak at 448 nm when the animal is pretreated with benzanthracene (BA). The P-450 content of the microsomes is increased when a rat is treated with BA and in regenerating liver BA has a greater effect on the cytochrome level. When protein synthesis is blocked by the administration of actinomycin D or puromycin there is a decrease in the P-450 content of the microsomes, but BA can still cause the conversion to the modified form in young female rats. The change also occurs in vitro when microsomes from young female rats are treated with BA; this change does not occur in adult female fats. It is proposed that the ability of BA to catalyze the change in the cytochrome structure depends upon the estrogen level of the animal.

Carbon-14-labeled benz(a)anthracene was introduced into a large-scale marine microcosm containing as ecosystem typical of the shallow coastal waters of the northeastern U.S. The removal of benz(a)anthracene and metabolites from the water column, their appearance and mixing into the sediments, and the production of carbon dioxide were traced. At the end of the experimental period, 29% of the hydrocarbon has been respired to CO/sub 2/, while the remaining extractable activity (43%) was evenly divided between parent compound and intermediate metabolic products. (3 diagrams, 3 graphs, 37 references, 3 tables)

SummaryMacrophages of human and mouse origins were shown to contain inducible aryl hydrocarbon hydroxylase activity. Mononuclear phagocytic cells derived from circulating blood monocytes of healthy human donors and peritoneal macrophages from untreated C57 B1/6 mice exhibited low levels of enzyme activity. For mice, aryl hydrocarbon hydroxylase specific activity of freshly explanted macrophages was 1/70th the enzyme activity found in liver. Aryl hydrocarbon hydroxylase activity for both human and mouse macrophages maintained in vitro in the presence of benzanthracene exceeded by 2-3 fold the enzyme specific activity of cells cultivated in the absence of inducer.

Aryl hydrocarbon hydroxylase (AHH) activity and inducibility were examined in mitogen-stimulated cultured lymphocytes from children with acute leukemia in remission, with nonleukemic malignancies, and with no family or personal history of malignant disease. Neither morphological differences nor differences in mitogen responsiveness were observed among the three sources of cells studied. Levels of constitutive and dibenzanthracene-induced AHH activity were found to be similar among the three groups by analysis of variance. However, when results were analyzed in terms of inducibility ratios, it was found that cells from leukemic children were significantly less inducible (p less than 0.005) than cells from unaffected children or children with nonleukemic malignancies. The reason for this difference became apparent when statistical criteria were employed for the pheontypic separation of individuals who were highly aromatic hydrocarbon responsive and minimally responsive. A significantly larger proportion (p less than 0.001) of leukemic children than unaffected children or children with nonleukemic malignancy were found to be minimally aromatic hydrocarbon responsive. Moreover, in patients with acute lymphoblastic leukemia relapsing while on therapy, longer durations of the first remission were correlated (r = 0.63, p less than 0.05) with the highly inducible AHH phenotype.

Analysis of carcinogenic methyl chrysenes in a complex sample matrix requires a combination of liquid-liquid partition and column chromatography to obtain a chrysene subfraction. Analytically interfering alkyl benzanthracenes are removed by a combination of a selective Diels-Alder reaction and column chromatography. Application to a coal-liquefaction product revealed 98 ppm of chrysene and 106 ppm of 3-methyl, 102 ppm of the 2-methyl, 64 ppm of the 6-methyl, and possibly 19 ppm of the 4- plus 5-methyl chrysenes.

Concentrations of aliphatic hydrocarbons from eicosane up to tritriacontane, and of polycyclic aromatic hydrocarbons from anthracene and phenanthrene up to the dibenzanthracenes have been determined by GC-MS in ambient aerosol samples from seven different locations in Belgium, the Netherlands and Bolivia. Some of the sampling stations were situated in urban environments, others in residential suburban or rural sites. At one sampling station, the distribution of these hydrocarbons between the particulate and the gas phase was further investigated. The distribution patterns of aliphatic and polyaromatic hydrocarbons as a function of molecular weight or carbon number are reported for typical summer and winter samples collected under the most frequently occurring stable meteorological conditions, at two urban and one rural site in Belgium. Furthermore, hydrocarbon levels for two suburban stations are reported in terms of average concentrations over summer and winter periods as well as of frequency distributions. They are based on weekly samples collected over the whole year. The aliphatic hydrocarbon series shows a typical alternating pattern with higher concentrations for the compounds with odd carbon number in the range C27–C31. This effect is believed to result from natural emissions of biological origin (e.g. vegetation), whereas a more continuous distribution is observed for the anthropogenic emissions with a maximum around C24–C26. Gas phase contributions above C24 to the total aliphatic hydrocarbon levels are not significant. The polyaromatic hydrocarbon series shows a constant distribution pattern with an expected increase in winter due to increased fossil fuel combustion processes, mainly of the higher molecular weight compounds, such as chrysene/benzanthracene, benzofluoranthenes and benzopyrenes. Among these, only chrysene/benzanthracene is also significant in the gas phase. At the background stations, the natural emission of higher odd aliphatic hydrocarbons is enhanced in summer samples as can be seen from the carbon preference index. For the background stations the combined interpretation of industrial activity data and prevailing wind direction data allows a reasonable understanding of the changes in pollution levels. However, this approach was not successful for the suburban samples of the survey studies, where changing meteorological factors such as variable winds, inversion conditions or rain simultaneously affected the organic composition of the aerosol.

Hepatoma cells derived from the Reuber H35 rat hepatoma express cytochrome P450 enzymes of two major families: polycyclic aromatic hydrocarbon-inducible forms are found in both differentiated and dedifferentiated cells while phenobarbital (PB)-inducible forms are found only in differentiated cells. We report here that (i) benzanthracene and PB induce P450 c mRNA in differentiated and dedifferentiated cells and (ii) dexamethasone and PB induce P450 b/e and/or P450 PB1 mRNAs in differentiated cells but not in dedifferentiated cells.

The effects of polycyclic aromatic hydrocarbons (PAH) such as benzanthracene (BA) and methylcholanthrene (MCA) on 3H-thymidine incorporation and aryl hydrocarbon hydroxylase (AHH) induction were assayed in mitogen-activated and non-activated splenic lymphocyte cultures derived from three strains of mice (C57BL, C3H and DBA/2). Results of three separate experiments on blastogenesis and the substrate induction of AHH were statistically significant. In mitogen-activated and non-activated lymphocytes from C57BL and C3H mice (AHH responsive strains) the percentage of blastogenesis induced by BA or MCA was higher than in lymphocytes from the non-responsive strain (DBA/2). On the basis of the PAH concentrations used MCA and BA were similar as inducers of blastogenesis and of AHH activity. AHH induction was measurable only in mitogen-activated lymphocytes and showed a non-linear relation to blastogenesis. In responsive strains, 10 microM oF BA or 1.5 microM of MCA induced AHH 2-5 fold, while in non-responsive mice induced AHH was very close to the basal level. This difference between the level of induction of lymphoblast formation and AHH in responsive and non-responsive strains of mice may be related to different subpopulations of lymphocytes in spleen or other lymphatic organs.

Samples from three cultivated soils and one from a roadside, all in Ontario, were found to contain less than 1 to 68 ppb of 1,2-Benzanthracene (BA). Two plots subjected to stubble (residue of wheat crop) burning annually for 15 years did not contain significant amounts of BA, although polyaromatic hydrocarbons, including BA, result from pyrolysis of most organic matter.

Chemical carcinogens are metabolized by numerous pathways catalyzed by enzymes in endoplasmic reticulum and other parts of the cell. Reactions in which functional groups are created (epoxidation and epoxide hydration, catalyzed by cytochrome P-450-linked monooxygenase and epoxide hydratase, respectively) are especially important in the activation of polycyclic hydrocarbon carcinogens to ultimate carcinogenic forms, although other enzymes may also participate in the activation of other chemical carcinogens. Numerous factors, genetic as well as environmental, affect the activities and the balance of different enzymes that participate in carcinogen activation and detoxification. The reasons why carcinogens act on specific target tissues are incompletely understood, although differences in enzyme profiles between tissues certainly contribute to the target tissue variability. Also, the location in the cell (endoplasmic reticulum, nuclear membrane, or other organelle) where the activation takes place is not known. It has been demonstrated that conjugated metabolites of carcinogens may be activated by spontaneous or enzymatic hydrolysis, and this raises the possibility of transport of metabolites to distant target tissues. The concept of metabolic activation of carcinogens by body's own enzymes has led to the development of short-term assay systems, which essentially measure the production of biologically active metabolites from potential carcinogens.

Human mitogen-stimulated lymphocytes, cultured in the presence of amosite asbestos (AS), demonstrated a slight increase in aryl hydrocarbon hydroxylase (AHH) activity compared with non-induced (control) cultures (P = 0.005). A much greater increase in enzyme activity occurred following addition of the inducers benzanthracene (BA) or cigarette tars (CT) to cell cultures (P less than 0.001 in both instances). Significant enzyme induction also occurred when AS fibers were first preincubated with CT or BA, washed with acetone, then added to lymphocyte cultures (P less than 0.003 in all instances). This increase in AHH activity was not as great, however, as the induction observed when BA or CT was added to cell cultures. No further increase in enzyme activity was noted when AS and CT or AS and BA were simultaneously added to culture lymphocytes (P greater than 0.070 in all instances). The results demonstrate that polycyclic aromatic hydrocarbons (PAH), such as BA and other components of CT, are adsorbed and transported by amosite AS particles. These AS-PAH complexes are capable of inducing AHH in cultured human lymphocytes.

The four possible isomers of benz(a)anthracene containing a cyclopenta-fused ring have been synthesized and characterized. These systems are of interest for structure-activity studies in bioactivation because of their predicted high level of activity. Formation of fused five-membered rings by intramolecular cyclodehydration, often difficult to accomplish, was found to be smoothly effected in anhydrous hydrofluoric acid (HF), provided the reactivity index (N/sub t/a) for the appropriate electrophilic addition was favorable. The dihydro polycyclic aromatic alcohols obtained from reduction of the corresponding keto cyclodehydration products were best dehydrated to the desired polycyclic aromatic hydrocarbons (PAH) by activity grade I neutral alumina in refluxing benzene. This dehydration proceeds in high yield without the formation of isomeric or polymeric side products that occurred even under such mild acid catalysis as p-toluenesulfonic acid.

Pulmonary alveolar macrophages (PAMs) obtained by bronchopulmonary lavage from 6 normal non-smoking volunteers were incubated with [3H]-benzo[alpha]pyrene to ascertain the normal metabolism and conjugation of polycyclic aromatic hydrocarbons. Through the use of a crude glucuronidase preparation, both glucuronic acid and sulfate conjugates were examined. Phenols and quinones were identified by high-pressure liquid chromatography as the principal free metabolites formed during 1 h incubation with benzanthracene induced PAMs. In addition, phenols and quinones were major substrates utilized by these cells for conjugation during the incubation period. The ranges of benzo[alpha]pyrene metabolites produced by PAMs from non-smokers were compiled and the variation in production as well as detoxification of proximate carcinogenic benzo[alpha]pyrene metabolites are presented.

Effects on the electronic structure of benzanthracene due to physical binding to bases of nucleic acid were studied by optically pumping the molecular triplet state and monitoring the subsequent decay. Since the triplet electronic states of molecules are sensitive to such perturbations, the observed changes in the total phosphorescence decay rate constants were used as a measure of the extent of molecular interaction. Additionally, changes in the triplet state zero field splitting parameters arising from the anisotropic spin—spin interaction of the triplet electrons were used as another measure of the extent of interaction. Changes in these parameters were observed for base pairs, polynucleotides and methylated adenines.

By using ultraviolet light flash excitation, the triplet (phosphorescence) decay time τ of a series of protonated (p) and deuterated (d) aromatic hydrocarbons dissolved in a fluffy freeze‐dried polystyrene matrix was studied as a function of oxygen pressure [O2] at 298°K. The quenching constants γ were calculated from linear plots of τ−1 as a function of [O2] and the ratios of γ(p)/γ(d) are 1.2±0.1 for anthracene and 1,2‐benzanthracene, 1.9±0.2 for pyrene, 1.4±0.2 for chrysene, and 2.5±0.4 for naphthalene. These results are interpreted in terms of Franck‐Condon factors and the energy transfer quenching model proposed by Kawaoka, Khan, and Kearns in which the 1Δg and 1Σg+ excited states of oxygen are generated, and in which the remaining energy is dissipated by the vibrational modes of the quenched aromatic molecules. In pyrene and in naphtalene, the 1Δg pathway appears to be more important than in chrysene and dominates over the 1Σg+ mechanism. No conclusions can be reached about the preferred mode of ene...

The amounts of five polynuclear aromatic hydrocarbons-fluoranthene, pyrene, benzo(a)anthracene, benzo(k)fluoranthene, and benzo(a)pyrene-extracted by six solvents with four extraction techniques have been determined for diesel exhaust particulate collected on Teflon-coated glass fiber filters. Samples were analyzed by high pressure liquid chromatography with fluorescence detection. Toluene and methylene chloride gave higher recoveries than methanol, isopropanol, acetonitrile, and acetone for benzo(a)anthracene, benzo(k)fluoranthene, and benzo(a)pyrene. Soxhlet extraction for two hours (approximately 48 cycles) with toluene or acetonitrile was more effective than simple mechanical agitation, ultrasonic agitation for 15 minutes or immersion in refluxing ‘solvent’ for two hours.

Several steroid responsive stromal cell strains were isolated from normal mouse endometrium. Both estrogen responsive and progesterone responsive strains were obtained. The estrogen responsive cells were also responsive to diethylstilbestrol (DES). The progesterone responsive strains were inhibited by estrone and estriol. One of the estrogen responsive cell strains, E041, was cloned in the presence and absence of 17-beta-estradiol (E2). Of 14 clones developed in the absence of E2 and screened for responsivity of growth, six were significantly responsive to E2. Six of 26 clones developed in the presence of E2 were responsive to E2. Microsomes isolated from these clones were shown to have aryl hydrocarbon hydroxylase (AHH) activity which was inducible with either benzanthracene (BA) or 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD). The basal levels of AHH activity were significantly reduced by E2 in E2 responsive clones. The TCDD induced levels of AHH activity in the E2 responsive and E2 non-responsive clones were significantly reduced by E2. The BA induced levels of AHH were significantly increased by E2 in one of the clones. These results show that mouse endometrial stroma consists of a number of populations of cells with different specific proliferative and metabolic responses to steroids.

With 1,2-benzanthracene and fluoranthene population of higher excited singlet states S n ( n > 1) by triplet-triplet annihilation is energetically possible. With both compounds a delayed fluorescence S n → S o from the highest accessible singlet states S n was found ( n = 3 for 1,2-benzanthracene and n = 4 for fluoranthene).

Absorption spectra of volatile aromatic hydrocarbon films, p -terphenyl, chrysene, benzanthracene and triphenylene, in the near and vacuum ultraviolet region down to 130 nm were measured under an atmosphere of Ar gas to suppress their sublimation. The spectrum of p -terphenyl is different from the spectra reported for other phases. This difference is explained in terms of the change of dihedral angles among the three benzene rings. The peak positions in the spectra of chrysene and bezanthracene agree with those in the solution spectra. The differences in the peak intensities are discussed in terms of the orientation of the films with the aid of MO calculations. The result of triphenylene suggests the presence of Davydov splitting.

In four experiments, concentrated glycerin suspensions of 7,12-dimethylbenz(a)anthracene (DMBA), or the water-soluble compounds, N-methyl-N-nitrosourea (MNU), N-ethyl-N-nitrosourea (ENU), and 4-nitroquinoline-N-oxide (4-NQO) were delivered into pockets in the mammary fat pads in female Sprague-Dawley rats. In a 90-day experiment, each of three groups of 20-22 rats were treated with either 25, 50, or 100 ..mu..g DMBA delivered to each of four sites in each rat per group. Dose-related responses were detected for incidence of rats with mammary adenocarcinoma (MAC), and for number of MAC per treated site. In a 120-day study, each of three groups of 20 animals were treated with either 250, 500, or 1000 ..mu..g MNU at each of 80 sites per group. Dose-related MAC responses were detected for incidence of rats with MAC, number of MAC per treated site, and time to detection of MAC. In two experiments of 90 days duration, groups of 20 females were treated with either 1000 ..mu..g ENU or 1000 ..mu..g 4-NQO at each of 80 sites per group. ENU produced a total of 27 MAC sites in 65% of the rats, and 4-NQO produced a total of 26 MAC in 60% of the rats. A comparison of the time to detection of allmore » MAC data for the three water-soluble compounds at the 1000 ..mu..g treatment level, or on the basis of moles per treatment, yielded a carcinogenic potency relationship of 4-NQO > ENU > MNU. 21 references, 2 figures, 1 table.« less

Chylomicrons obtained from the thoracic duct of rats fed [3H]7,12-dimethylbenz(a)anthracene (DMBA), a polycyclic aromatic hydrocarbon, were infused intravenously into rats with bile fistulas. Over 17 hr, 55.9 +/- 3.2% (mean +/- SEM) of the radioactivity was recovered in bile and 6.7 +/- 0.5% in urine. Minor amounts were deposited in liver, kidneys and epididymal fat pads. Injection of DMBA in ethanolic solution gave a similar pattern, while biliary DMBA metabolites resulted in higher recovery in urine and lower recovery in fat. In conclusion, the major part of chylomicron DMBA is rapidly excreted via the biliary route, while a fraction is probably retained in adipose tissue.

C3H/StWi mice spontaneously lost their exogenous MMTV (MMTV-S) in 1958 and became a low mammary cancer subline. They do not ordinarily express their endogenous MMTV provirus as virions. Virigin C3H/StWi females were exposed to chemical carcinogens, 7-12 dimethyl(α)benzanthracene (2,6 mg) and urethane (200 mg) in the presence or absence of chronic hormonal stimulation of the mammary gland by pituitary isografts. By 10 months of age, mammary tumors developed in 40% of the females given DMBA, and in 59% of those given DMBA and carrying pituitary isografts. With urethane treatment alone, 14% of the mice developed mammary cancer during a 12-months period; however, 74% of the mice bore mammary tumors when pituitary isografts were present. None of the females given pituitary isografts alone developed mammary cancer during the experimental period. Mammary tumors from each group were evaluated by radioimmune competition assay, immunoperoxidase and electron microscopy to determine the extent of endogenous MMTV gene expression. In addition, the mammary glands of some of the non-tumor-bearing mice were studied by whole mount and by histology to determine the type, extent, and number of mammary dysplasias present in each group. In general, there was no correlation between tumor incidence and the presence of mammary tumor virus antigens. Of 32 mammary tumors tested in all groups, 10 were positive at low levels for MMTV antigens. In the positive tumors, the internal MMTV gag gene antigen, p28, was prevalent. Immunoperoxidase studies on these same tumors gave quantitatively similar results. It is apparent from these observations that chemical carcinogenesis of mouse mammary glands does not require or even favor the complete expression of endogenous MMTV genes. In this study, hormonal stimulation of the glands during and after exposure to the carcinogen increases the rate of tumorigenesis, but does not seem to favor MMTV gene expression. We conclude that C3H/StWi mice are susceptible to DMBA and urethane induction of mammary cancer and to an extent this process is positively influenced by the presence of hormonal stimulation. Our results support the view that a qualitative or quantitative shift in the expression of MMTV proviral sequences does not occur during tumor development.

Studies were conducted to determine whether normal and/or neo-plastic (MCF-7) human breast epithelial cells contain the microsomal aryl hydrocarbon hydroxylase (AHH) which catalyses the conversion of polycyclic aromatic hydrocarbons (PAH) to carcinogenic intermediates. Low constitutive levels of AHH activity were found in homogenates of both normal human breast epithelial and MCF-7 cells. The addition of 7,12-dimethylbenz(a)anthracene (DMBA) to the culture medium of either cell type significantly increased AHH activity. Peak induction of hydroxylase activity occurred following the in vitro addition of 10 μM DMBA. A time course of DMBA-induced AHH activity in both normal human breast epithelium and MCF-7 cells revealed maximal induction 16 hr after 10 μM DMBA was added to the culture medium. Benzo(a)pyrene (BP), 3-methylcholanthrene (MCA) and benz(a)anthracene (BA) also induced AHH activity in normal and MCF-7 cells. For example, the addition of 10 μM BP to the culture medium of either normal human breast epithelial or MCF-7 cells for 16 hr increased AHH activity 13.8 and 65.3-fold, respectively. For all PAH, the magnitude of AHH induction was substantially greater in MCF-7 than normal breast epithelial cells. Finally, α-naphthoflavone inhibited BA-induced AHH activity in MCF-7 cells. The study demonstrates the presence of a PAH-inducible AHH enzyme(s) in normal human breast epithelial cells grown in primary culture and in the human breast tumor cell line, MCF-7.

Syncephalastrum racemosum UT-70 and Cunninghamella elegans ATCC 36112 metabolized 7,12-dimethylbenz[a]anthracene (7,12-DMBA) to hydroxymethyl metabolites as well as 7-hydroxymethyl-12-methylbenz[a]anthracene trans-3,4-, -5,6-, -8,9-, and -10,11-dihydrodiols. The 7,12-DMBA metabolites were isolated by reversed-phase high-performance liquid chromatography and identified by their UV-visible absorption, mass, and nuclear magnetic resonance spectral characteristics. A comparison of the circular dichroism spectra of the K-region (5,6-position) dihydrodiol of both fungal strains with those of the 7,12-DMBA 5S,6S-dihydrodiol formed from 7,12-DMBA by rat liver microsomes indicated that the major enantiomer of the 7-hydroxymethyl-12-methylbenz[a]anthracene trans-5,6-dihydrodiol formed by both fungal strains had a 5R,6R absolute stereochemistry. Direct resolution of the fungal trans-5,6-dihydrodiols by chiral stationary-phase high-performance liquid chromatography indicated that the ratios of the R,R and S,S enantiomers were 88:12 and 77:23 for S. racemosum and C. elegans, respectively. These results indicate that the fungal metabolism of 7,12-DMBA at the K region (5,6-position) is highly stereoselective and different from that reported for mammalian enzyme systems.

Phenobarbitone (PB) was toxic to rat liver fibroblasts within the concentration range 0.1–10 mM but was toxic to rat hepatocytes only at concentrations greater than 2 mM. This increase in cytotoxicity coincided with a decline in the PB-mediated inducibility of the microsomal monooxygenase (MMO) system. Benzanthracene (BA) was not cytotoxic to either cell type at maximal inducing concentration. Exposure of the cells to a mixture of PB + BA at maximal inducing concentrations produced synergistic toxicity to the fibroblasts, due possibly to PB-mediated induction of BA reactive metabolite formation.

The immunosuppresive effects of topically applied 9, 10 dimethyl 1, 2 benzanthracene (DMBA) were investigated in the Syrian Golden hamster. Tri-weekly doses of DMBA were administered, zith some hamsters receiving both DMBA and X-radiation. DMBA and DMBA-plus-radiation groups demonstrated decreased immune responsiveness relative to their control counterparts. Potential immuntosuppressive effects of carcinogen and carcinoma are discussed.

Aryl hydrocarbon hydroxylase (AHH) activity was measured in cultured pulmonary alveolar macrophages (PAMs) (n = 12) and peripheral blood lymphocytes (n = 72) from unrelated baboons. It was determined that optional AHH induction was observed in PAMs when cells were cultured for 24 or 48 hours in the presence of a 15 μM concentration of the inducer, benzanthracene (BA). Maximal enzyme activity was observed in mitogen-activated lymphocytes when cells were cultured for 96 or 120 hours in the presence of 10 μM BA concentration. Additionally, there were no differences in PAM or lymphocyte AHH induction when cells were cultured in different types of culture medium (P > 0.10 in all instances, using paired, 2-tailed, Student's t-test). Similarly, no differences were observed between PAM AHH activity when human AB serum or autologous baboon serum was used in the culture medium (P > 0.30). However, slightly higher BA-induced AHH levels were noted in lymphocytes cultured in the presence of autologous baboon serum as compared with human AB serum (P < 0.02). Using optimal culture conditions for PAMs and lymphocytes from individual baboons a 6.5-fold interindividual variation in PAM and a 30-fold variation in lymphocyte BA-induced AHH levels were observed (n = 8 and 64, respectively). These studies document that AHH is measurable in cultured baboon PAMs and lymphocytes and that there is wide interindividual variation in BA-induced AHH levels. The distribution of AHH activity appears to be similar to that observed in the human population.

The 13C13C spin coupling constants have been determined in substituted [1-13C]tetrahydronaphthylenes, [5-13C]hexahydrobenzanthracenes and [5-13C]benzanthracene. In addition, the 13C13C spin coupling constants for 7-hydroxy[7-13C]benzopyrene, trans-7,8-dihydro[7-13C]benzopyrene-7,8-diol and trans-7,8-dihydro[10-13C]benzopyrene-7,8-diol are reported, together with the one-bond carbon-carbon coupling constants between C-4 and C-5 in selected 4,5-disubstituted benzopyrenes. Values for the directly bonded coupling constants and long-range coupling constants are similar to those reported previously for other aromatic and aliphatic systems. Substituent effects on carbon-carbon coupling are compared for similarly substituted cyclic and acyclic systems.

The response of the hair follicle apparatus to topical 9, 10-dimethyl-benzanthracene applications was studied in several strains of mice and rats. Early follicular destruction in mice was associated with subsequent formation of large number of epithelial tumors. Preserved follicular structures in rats proliferated with the formation of low incidence of adenomas and trichoepitheliomas. Hair nevi, hairfollicle nevi and trichofolliculomas, unrelated to treatment, were observed in several animal strains.