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PubMed1985

Notification and risk assessment for bladder cancer of a cohort exposed to aromatic amines. III. Mortality among workers exposed to aromatic amines in the last beta-naphthylamine manufacturing facility in the United States.

A retrospective cohort mortality study was conducted among workers employed at the last facility in the United States that manufactured beta-naphthylamine (BNA), a recognized human bladder carcinogen. This study was conducted in conjunction with a pilot project in which workers were notified of the health risks associated with exposures to carcinogenic amines. Cause-specific mortality for 1,312 male workers employed between 1940 and 1972, and followed through 1979, was compared with the mortality of the general population in the United States. Two deaths from bladder cancer were observed while 0.7 such deaths were expected. Due to the use of these potent carcinogenic amines, it had been anticipated that more bladder cancer deaths would be found in this population. The reasons for the small number of bladder cancer deaths could have been the low percentage of the work force exposed, an inadequate latency period, and/or the high survival rate for bladder cancer. In fact, a notification and medical screening project recently conducted in this same population found an additional 11 bladder cancer cases. This suggests that mortality may not always be an adequate indicator of disease risk.

2-Naphthylamine↗
PubMed1983

Carcinogenicity of N-nitrosomethyl(2-oxobutyl)amine and N-nitrosomethyl-(3-oxobutyl)amine in Syrian hamsters with special reference to the pancreas.

Studies with oxidized derivatives of N-nitrosodi-n-propylamine suggested a structure-activity relationship between pancreatic cancer induction in Syrian hamsters and position and degree of nitrosamine oxidation. To elucidate the importance of the position of the oxidized substituent relative to the N-nitroso group in pancreatic carcinogenesis, we compared the toxicity and carcinogenicity of two substituted methylbutylnitrosamines. N-Nitrosomethyl(2-oxobutyl)amine (M-2-OB) and N-nitrosomethyl(3-oxobutyl)amine (M-3-OB) were given in equitoxic doses to male and female Syrian hamsters. The 50% lethal doses for M-2-OB and M-3-OB in males and females, respectively, were 92 and 160 and 705 and 810 mg/kg body weight. M-2-OB, although given in significantly smaller doses (minimum dose, 2.3 mg/kg body weight) than was M-3-OB (minimum dose, 17.6 mg/kg body weight), induced a much broader spectrum of neoplasms (in 17 tissues), whereas M-3-OB induced tumors in only 5 tissues and had no carcinogenic effect in the pancreas. M-2-OB, however, produced pancreatic ductular-ductal adenocarcinomas in over 90% of the males and 67% of the females, even at the lowest doses (2.3 and 4.0 mg/kg, respectively). Although both compounds caused a similar incidence of morphologically equivalent neoplasms (mostly adenocarcinomas) in the nasal and paranasal cavities, the remaining distribution of affected tissues differed significantly. M-2-OB predominantly affected the lip (epitheliomas, squamous cell carcinomas), liver (cholangiomas and cholangiocarcinomas), and flank organ (epitheliomas, squamous cell carcinomas). The principal target organs for M-3-OB were the cheek pouch (papillomas, squamous cell carcinomas) and trachea (polyps). In contrast to M-2-OB, M-3-OB did not induce renal and urethral tumors. These findings indicate the importance of the 2-oxo group as a prerequisite for the carcinogenicity of methylalkylnitrosamines in the hamster pancreas; however, a methyl group in one aliphatic chain, alpha to the N-nitroso function, appears to cause the molecule to lose its selectivity for the pancreas.

Animals↗
PubMed2002

Comparison of electrophilic amination reagents for N-amination of 2-oxazolidinones and application to synthesis of chiral hydrazones.

Comparison of several hydroxylamine-based electrophilic ammonia equivalents in the N-amination of 2-oxazolidinones revealed that O-(p-nitrobenzoyl)hydroxylamine (NbzONH(2)) and sodium hydride in dioxane is a superior reagent combination for this purpose. Practical preparations of a variety of chiral N-acylhydrazones by this method gave yields ranging from 45 to 95%. Methods for exchange or removal of the aldehyde component have been developed, making this a general route to chiral N-acylhydrazones of interest for asymmetric synthesis applications.

Amination↗
PubMed2006

Regioselective copper-catalyzed amination of bromobenzoic acids using aliphatic and aromatic amines.

A chemo- and regioselective copper-catalyzed cross-coupling procedure for amination of 2-bromobenzoic acids is described. The method eliminates the need for acid protection and produces N-aryl and N-alkyl anthranilic acid derivatives in up to 99% yield. N-(1-Pyrene)anthranilic acid has been employed in metal ion-selective fluorosensing. Titration experiments showed that this pyrene-derived amino acid forms an equimolar complex with Hg(II) in water resulting in selective fluorescence quenching even in the presence of other metal ions such as Zn(II) and Cd(II).

Amination↗
PubMed1986

Binding of psychoactive drugs to rat brain amine receptors, measured ex vivo, and their effects on the metabolism of biogenic amines.

Ex vivo receptor binding experiments and measurements of the concentrations of the amine metabolites HVA, MOPEG-SO4 and 5-HIAA were carried out on rat brain tissues to analyse the effects of several neuroleptics (haloperidol, chlorpromazine, thioridazine, clozapine, fluperlapine), antidepressants (amitriptyline, mianserin, zimelidine) and other drugs (pizotifen, ketanserin, prazosin) on brain aminergic systems. It was found that in all cases where drugs reduced 3H-haloperidol binding to striatal D2-receptors ex vivo (haloperidol, chlorpromazine, thioridazine, clozapine, fluperlapine, pizotifen, zimelidine), the same drugs caused a pronounced increase, in vivo, in the striatal HVA-concentration, i.e. an increase in DA-turnover. The HVA-increase was directly proportional to the extent of the reduction of 3H-haloperidol binding. These findings suggested that in the 3H-haloperidol assay binding of drugs is to functional D2-receptors regulating the release of DA. In contrast, reduction of binding of 3H-prazosin to brain stem alpha 1-receptors ex vivo (all drugs except zimelidine) was only associated with an in vivo increase in the MOPEG-SO4 concentration in some cases (haloperidol, chlorpromazine, thioridazine, clozapine, fluperlapine, ketanserine). Similarly, reduction of 3H-spiperone binding to 5-HT2-receptors in the frontal cortex (all agents except prazosin and zimelidine) was only associated with an increase in the 5-HIAA concentration in certain cases (thioridazine, clozapine, fluperlapine, pizotifen, ketanserin). The present data indicate that in the brain alpha 1- and 5-HT2-receptors do not seem to be linked directly to the processes which govern the turnover of the neurotransmitters DA, NA or 5-HT.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1982

Transglutaminase may mediate certain physiological effects of endogenous amines and of amine-containing therapeutical agents.

Transglutaminase mediation of the effects of certain primary amines and alcohols may be important in receptor coupling to physiological responses. Many of the therapeutic and toxic side effects of drugs also may be related to their covalent linkage of glutamine residues of key regulatory proteins through the catalytic action of transglutaminase. This paper suggests that important therapeutic agents such as digoxin, tetracycline, adriamycin, and actinomycin D may have some effects related to transglutaminase action.

Amines↗
PubMed1986

pH dependence of deuterium isotope effects and tritium exchange in the bovine plasma amine oxidase reaction: a role for single-base catalysis in amine oxidation and imine exchange.

The pH dependence of steady-state parameters for [1,1-1H2]- and [1,1-2H2]benzylamine oxidation and of tritium exchange from [2-3H]dopamine has been measured in the bovine plasma amine oxidase reaction. Deuterium isotope effects on kcat/Km for benzylamine are observed to be constant, near the intrinsic value of 13.5, over the experimental pH range, indicating that C-H bond cleavage is fully rate limiting for this parameter. As a consequence, pKa values derived from kcat/Km profiles, 8.0 +/- 0.1 (pK1) and 9.0 +/- 0.16 (pKs), can be ascribed to microscopic pKa values for the ionization of an essential active site residue (EB1) and substrate, respectively. Profiles for kcat and Dkcat show that EB1 undergoes a perturbation from 8.0 to 5.6 +/- 0.3 (pK1') in the presence of substrate; additionally, a second ionization, pK2 = 7.25 +/- 0.25, is observed to mediate but not be essential for enzyme reoxidation. The pH dependence of the ratio of tritium exchange to product formation for dopamine also indicates base catalysis with a pKexch = 5.5 +/- 0.01, which is within experimental error of pK1'. We conclude that the data presented herein support a single residue catalyzing both substrate oxidation and exchange, consistent with recent stereochemical results that implicate a syn relationship between these processes [Farnum, M., & Klinman, J.P. (1985) Fed. Proc., Fed. Am. Soc. Exp. Biol. 44, 1055]. This conclusion contrasts with earlier kinetic data in support of a large rate differential for the exchange of hydrogen from C-1 vs. C-2 of phenethylamine derivatives [Palcic, M.M., & Klinman, J.P. (1983) Biochemistry 22, 5957-5966].(ABSTRACT TRUNCATED AT 250 WORDS)

Amine Oxidase (Copper-Containing)↗
PubMed2005

Quantitation of carcinogenic heterocyclic aromatic amines and detection of novel heterocyclic aromatic amines in cooked meats and grill scrapings by HPLC/ESI-MS.

A tandem solid-phase extraction method was used to isolate carcinogenic heterocyclic aromatic amines (HAAs) from cooked meats. The following 10 HAAs were identified by HPLC/ESI-MS/MS: 2-amino-9H-pyrido[2,3-b]indole (2-AalphaC), 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeAalphaC), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3-methylimidazo[4,5-f]quinoxaline (IQx), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (8-MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx), 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline (7,8-DiMeIQx), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-1,7,9-trimethylimidazo[4,5-g]quinoxaline (7,9-DiMeIgQx), and 2-amino-1-methylimidazo[4,5-b]quinoline (IQ[4,5-b]); the latter HAA has not previously been reported in cooked meats. The concentrations of these HAAs ranged from <0.03 to 15 ppb in cooked meats and poultry, to 75 ppb in cooked beef extract, and to 85 ppb in grill scrapings. The product ion scan mode was used to confirm the identities of these HAAs. Six other compounds were detected that appear to contain the N-methylimidazoquinoxaline skeleton on the basis of their product ion spectra, and these compounds are probable isomers of IQx, 8-MeIQx, and DiMeIQx. A number of known HAAs and novel HAAs of unknown genotoxic potential are formed at appreciable levels in cooked meats.

Amines↗
PubMed1971

Microbial oxidation of amines. Spectral and kinetic properties of the primary amine dehydrogenase of Pseudomonas AM1.

1. An improved procedure is reported for purification of the amine dehydrogenase from methylamine-grown Pseudomonas AM1 which yielded a product homogeneous by sedimentation and disc-electrophoretic analysis, with molecular weight of 133000. 2. The purified enzyme had absorption maxima at 280 and 430nm. On aging, a third peak appeared at 325nm, and the 430nm peak decreased in intensity. This spectrum was independent of pH. 3. Addition of 2.5mm-semicarbazide, phenylhydrazine, hydrazine or hydroxylamine produced modified spectra with maxima respectively at 400, 440, 395 and 425nm. 4. Aerobic addition of methylamine resulted in a bleaching of the 430nm peak and the appearance of a new one at 325nm. This spectral change was retained after removal of the methylamine by dialysis. The original spectrum could be restored on addition of phenazine methosulphate. 5. Addition of borohydride partially inactivated the enzyme and produced spectral changes similar to those observed with methylamine. Pre-treatment with methylamine prevented the inactivation by borohydride. The degree of inactivation could be increased by alternate phenazine methosulphate and borohydride treatments. 6. The addition of methylamine or borohydride each caused shifts in the fluorescence emission maximum from 348 to 380nm. 7. Lineweaver-Burk plots of reciprocal activity against reciprocal concentration of either of the substrates n-butylamine or phenazine methosulphate were consistent with a mechanism that involves interconversion of two free forms of the enzyme by the two substrates. 8. The enzyme, although spectrally modified, was not inactivated by dialysis against diethyldithiocarbamate, and contained about 0.27 g-atom of copper/mol, with small traces of cobalt, iron and zinc. 9. Conventional methods of resolution did not release the prosthetic group. Heat denaturation after treatment of the enzyme with methylamine liberated a yellow chromophore which did not reactivate resolved aspartate aminotransferase, and whose spectral, electrophoretic and fluorescence properties did not agree with any recognizable pyridoxal derivatives. 10. Despite the inconclusive results with the isolated chromophore, the observations on the enzyme suggest that it may contain a pyridoxal derivative bound as a Schiff's base which is converted into the pyridoxamine form on aerobic treatment with methylamine and reconverted into the pyridoxal form with phenazine methosulphate. 11. The copper detected is probably not involved in the enzyme mechanism, since most copper-chelating agents are not inhibitory, and since the enzyme does not react with oxygen.

Amines↗
PubMed1971

Microbial oxidation of amines. Partial purification of a mixed-function secondary-amine oxidase system from Pseudomonas aminovorans that contains an enzymically active cytochrome-P-420-type haemoprotein.

1. Crude extracts of Pseudomonas aminovorans grown on methylamine, di-methylamine, trimethylamine or trimethylamine N-oxide contain an enzyme or enzyme system catalysing the NADH- or NADPH- and oxygen-dependent oxidation of dimethylamine to methylamine and formaldehyde. 2. The enzyme has been partially purified about five-fold. It is unstable, but can be stabilized by addition of 5% (v/v) ethanol. 3. The partially purified enzyme will utilize either NADH (K(m) 6.5mum) or NADPH (K(m) 13.2mum): The following secondary amines have been shown to be substrates: dimethylamine, ethylmethylamine, diethylamine, methyl-n-propylamine, ethyl-n-propylamine, n-butylmethylamine and N-methylethanolamine. The K(m) values and comparative reaction rates for each substrate have been determined. Where the alkyl groups are different, the aldehyde products are derived from both groups. 4. The enzyme system has a pH optimum of 6.8 and is inhibited by mercurials, thiol compounds, cyanide and carbon monoxide. 5. The partially purified preparation had a spectral maximum at 412nm with shoulders at 427 and 550nm. Reduction with dithionite or NAD(P)H bleached the 412nm peak, and the shoulder at 427nm became a peak. Additional peaks appeared at 550 and 580-588nm. Reduction of a preparation bubbled with carbon monoxide enhanced and sharpened the Soret peak and caused it to shift to 422nm. 6. Analysis of the preparation showed the presence of flavin, acid-extractable iron and non-acid-extractable iron in the proportion 1.1:1.9:1. On reduction with dithionite or NADPH the preparation showed an electron-paramagnetic-resonance signal at around g=1.946.

Amines↗
PubMed1998

Influence of growth mode and sucrose on susceptibility of Streptococcus sanguis to amine fluorides and amine fluoride-inorganic fluoride combinations.

This study evaluated the susceptibility to amine fluorides (AmFs) of planktonic and biofilm cultures of Streptococcus sanguis grown with and without sucrose. Cultures were incubated with AmFs (250 mg of fluoride liter-1) for 1 min. The susceptibility of biofilms was less than that of the planktonic form and was further decreased by growth in the presence of sucrose.

Amines↗
PubMed1988

Intra-oral retention of fluoride by bovine enamel from amine fluoride toothpaste and 0.4% amine fluoride liquid application.

The purpose of this study was to compare in vivo fluoride accumulation in enamel and in enamel lesions from a single topical fluoride application and daily toothbrushing with a fluoride dentifrice. Amine fluoride preparations were used for both products. Intra-oral appliances with bovine enamel specimens were worn by volunteers during a period of seven weeks. After this period, the specimens were analyzed for fluoride uptake and change in demineralization susceptibility. The results demonstrated that lesions had a high fluoride uptake capacity. Fluoride content values increased by 25-30 micrograms/cm2 during a single topical application, as compared with 10-15 micrograms/cm2 during seven weeks of toothbrushing. About half the fluoride acquired as a result of topical treatment was lost during subsequent exposure to the oral fluids when no further fluoride supplementation was given. The uptake of fluoride by sound enamel was comparatively small, regardless of the use of fluoride dentifrice or application. The presence of mature plaque at the time of fluoride application did not affect the amounts of fluoride delivered. Acid susceptibility tests showed that the enamel solubility exhibited a negative correlation with fluoride content of the specimens.

Amines↗
PubMed2002

Combined use of tertiary amine parasympathomimetics with a quaternary amine parasympatholitic--a new perspective to use parasympathomimetic drugs for systemic analgesia.

The interactions on antinociception between a muscarinic agonist arecoline (arec), an anticholinesterase physostigmine (physo) which both cross CNS, and a peripherally acting antimuscarinic hyoscine-N-butyl bromide (hyo), were assessed by tail flick test in mice. All drugs were administered intraperitoneally (i.p.). While hyoscine-N-butyl bromide (0.15 and 4.00 mg/kg, i.p.) did not produce antinociception, physostigmine salicylate (0.3 mg/kg, i.p.) and arecoline hydrobromide (8.00 mg/kg, i.p.) exerted significant antinociceptive effect. In combined applications, physo + hyo (0.075 + 0.15; 0.15 + 0.30; 0.30 + 0.60 mg/kg) and arec + hyo (1.00 + 0.50; 2.00 + 1.00; 4.00 + 2.00; 8.00 + 4.00 mg/kg), respectively, produced significant antinociception and the tail flick latencies produced by physo 0.30 + hyo 0.60 mg/kg and arec 8.00 + hyo 4.00 mg/kg were not significantly different from those of physo 0.30 mg/kg and arec 8.00 mg/kg, respectively, showing that hyo did not antagonise the antinociceptive effects of physo and arec. We believe that combining an centrally acting cholinergic drug applied systemically with a peripherally acting (quaternary amine) antimuscarinic compound might be used as an effective analgesic in clinical practice.

Amines↗
PubMed1978

[Kinetic and spectral parameters of the amines oxidative N-dealkylation with participation of the liver microsomal cytochrome P-450. Amines oxidation with organic hydroperoxides].

Kinetics of demethylation of a number of amines involving hepatic microsomal cytochrome P-450 and organic hydroperoxides (tret-butyl- and cumylhydroperoxide) have been investigated. Decomposition rate constants for the substrate-cytochrome P-450-ROOH complexes have been determined in a generalized form. Activation parameters, deltaH* and deltaS*, are calculated for decomposition of the complexes. There is a linear relation between deltaH* and deltaS*: deltaH*=18.7 kcal + 333 degrees K deltaS*. Compensation relationship is characterized by the value of alpha=333 degrees K/Taverage=1.11. The nature of the limiting step in the cytochrome P-450-NADPH-O2-system and the cytochrome P-450-ROOH-system is discussed.

Amines↗
PubMed1995

Identification of new mutagenic heterocyclic amines and quantification of known heterocyclic amines.

2-amino-1-methyl-6-(4-hydroxyphenyl)imidazo[4,5-b]pyridine (4'-OH-PhIP) was mutagenic, inducing 180 revertants of Salmonella typhimurium TA98 per 100 micrograms with S9 mix and was formed by heating a mixture of creatine, tyrosine and glucose. It was detected in broiled beef at a level of 21.0 ng per g of broiled beef, which is comparable to the level of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Two new mutagens were isolated from bacteriological-grade beef extract using a new Salmonella tester strain, YG1024, which has a much higher O-acetyltransferase level than TA98. These mutagens were identified as 2-amino-4-hydroxymethyl-3,8-dimethylimidazo[4,5-g]quinoxaline (4-CH2OH-8-MeIQx) and 2-amino-1,7,9-trimethylimidazo[4,5-g]quinoxaline(7,9-DiMeIgQx++ +). The amounts of these mutagenic heterocyclic amines (HCAs) in beef extract were 6.0 ng and 53 ng per g of beef extract, respectively. 4-CH2OH-8-MeIQx induced 326,000 revertants of YG1024 and 99,000 revertants of TA98 per microgram with S9 mix, while 7,9-DiMeIgQx induced 13,800 and 670 revertants of YG1024 and TA98, respectively, per microgram in the presence of S9 mix. The levels of nine previously reported HCAs in cooked meats and fish and in beef extract were determined quantitatively. The level of PhIP was highest (0.56 approximately 69.2 ng/g), followed by that of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) (0.64 approximately 6.44 ng/g), and those of other HCAs were 0.03 approximately 2.50 ng/g. Mainstream smoke condensates of five Japanese brands of cigarettes contained four HCAs, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 2-amino-9H-pyrido[2,3-b]indole (A alpha C) and 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeA alpha C), at levels of 0.02 approximately 13.5 ng per cigarette and sidestream smoke condensates of two brands of cigarettes contained these HCAs at levels of 0.14 approximately 2.72 ng per cigarette. PhIP was not detected in any sample of mainstream or sidestream smoke condensate.

Amines↗
PubMed1983

Heparin adsorbing capacities at physiological pH of three poly(amido-amine) resins, and of poly(amido-amine)-surface-grafted glass microspheres.

Three poly(amido-amine)s of similar structure in the form of highly hydrophilic crosslinked resins, have been prepared, and tested for their heparin-adsorbing capacity at physiological pH. They showed different capacities, and their capacities were related to their basicities. One of the same polymers was grafted on the surface of glass microspheres. After treatment, it was shown that the microspheres could adsorb significant amounts of heparin. In all cases most of the adsorbed heparin was hardly eluted with saline, plasma, or blood, but could be recovered by eluting with 0.1 M NaOH. The resins were found to have some haemolytic properties, but no haemolysis was observed with the grafted microspheres.

Adsorption↗
PubMed1986

Vascular changes associated with growth of primary and transplantable pancreatic adenocarcinomas induced in Syrian golden hamsters by N-nitrosobis(2-oxopropyl)amine (BOP) and N-nitrosobis(2-hydroxypropyl)amine (BHP).

Microangiographic and histological methods were used to characterize vascular structure of primary and transplantable pancreatic adenocarcinomas induced by propylnitrosamines in Syrian golden hamsters. Originally of well-differentiated tubular morphology, serial transplantation subcutaneously to the back region was not associated with change in histopathological pattern or increase in invasive or metastatic potential. In contrast, pancreatic subserosal grafts displayed prominent invasion of surrounding tissues. Whereas primary tumors induced by N-nitrosobis(2-oxopropyl)amine (BOP) and those transplanted subserosally were characterized by hypovascularity, subcutaneous transplantation resulted in hypervascular tumors. Encasement, which is defined as invasion of normal arteries by the tumor, showing uneven caliber, irregular outline, appeared on earlier microangiographic findings rather than luminal irregularity, which is change of tumor vessels in neovascularization and occurs in tumor blood vessels subsequent to transplantation. The vascular component of subcutaneously transplanted tumors had a total vessel length ranging from 9.2 +/- 0.7 mm to 18.1 +/- 1.1 mm, a total vessel surface from 2.5 +/- 0.4 mm2 to 9.3 +/- 0.6 mm2 and a total vessel volume from 0.07 +/- 0.02 mm3 to 0.49 +/- 0.04 mm3, indicating that the vessels were of relatively large diameter and short length.

Adenocarcinoma↗