Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Dimethylamines”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,459 records · Page 81Linked to original sources
PubMedDate not supplied

[Effect of small amounts of 2,4-dichlorophenoxyacetic acid derivatives on thiamine and riboflavin metabolism in the animal body].

Administration of the herbicide 2,4-DN (amine salt of 2,4-dichlorphenoxyacetic acid) to weanling rats in a dose of 1/20.000 and 1/2000 of the LD50 for 3 months brought about a 40-50% reduction of thiamine content in the organs and tissues of experimental animals as compared with control. The herbicide was introduced into a balanced formula diet. In the liver of rats given 2,4-DA, there was a 2-fold decrease in the content of flavine adeninedinucleotide, whereas the content of flavine mononucleotide showed a 2-fold rise. Besides, the rats given a lesser herbicide dose manifested a reduced excretion of riboflavine with urine, and an inhibition of liver succinate dehydrogenase. The same animals demonstrated an increase in the relative mass of the adrenals with a concurrent diminution in them of ascorbic acid content.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1981

[Role of age in N-nitrosodimethylamine- and N-dimethylnitramine-induced carcinogenesis in Rana temporaria L. amphibians].

A comparison of the reactions of adult and juvenile amphibians Rana temporaria showed that the host sensitivity (latency and tumour incidence) of both groups of animals to the carcinogenic action of N-nitrosodimethylamine and dimethylnitramine was of the same order. However, a "shift" in organ sensitivity (different organotropic effect) was observed. The predominance of hepatocellular cancer in adult and hemocytoblastosis in young Rana temporaria was significant (P less than 0,01). The mechanisms of these "shifts" are unknown, but a role of the metabolic and reparative processes has been suggested.

Aging↗
PubMed1981

Mutagenicity studies in Salmonella typhimurium on some carcinogenic N-nitramines in vitro and in the host-mediated assay in rats.

N-Nitrodimethylamine, N-nitrodiethylamine, N-nitromorpholine and their N-nitroso analogs, N-nitrosodimethylamine, N-nitrosodiethylamine, and N-nitrosomorpholine, were tested in Salmonella typhimurium strains TA100 and TA1530. The mutagenicity of all compounds, except N-nitrodiethylamine, was demonstrated in liquid incubation assays in at least one of the tester strains; it required the presence of a postmitochondrial supernatant from the liver of Aroclor-treated rats, reduced nicotinamide adenine dinucleotide phosphate-generating system, and oxygen. When compared on a molar basis with their N-nitroso analogs, N-nitromorpholine was about 10 times less mutagenic and N-nitrodimethylamine about 70 times less mutagenic. Addition of disulfiram to the assays at a final concentration of 0.1 mM efficiently inhibited mutagenesis by all nitro and nitroso compounds; ascorbic acid at a 7.4 mM concentration produced less inhibition. Mutagenic activity of the three nitramines was also determined in the host-mediated assay in rats. After p.o. administration of each of the N-nitramines, cells of S. typhimurium strains TA1530 and TA100 that had been injected i.p. were isolated from the peritoneal liquid after 1, 3, and 6 hr. All three nitramines were found to be mutagenic for strain TA1530 but not for TA100. Mutation frequencies (number of histidine revertants per 10(6) surviving cells) were in the descending order N-nitromorpholine greater than N-nitrodiemethylamine greater than N-nitrodiethylamine. After a p.o. dose of N-nitrodiethylamine to rats, bacteria were also isolated from liver, lungs, and kidneys. Mutation frequency was highest in bacteria recovered from the liver but was not increased in those obtained from lungs and kidneys. The data suggest that carcinogenic nitramines exert their mutagenic effects through the formation of alkylating intermediates.

Animals↗
PubMed1981

[Structural-functional characteristics of photosynthetic reaction centers extracted by treatment with lauryldimethylamine oxide from Rhodopseudomonas sphaeroides (wild type)].

A method for isolation of photoactive reaction centers from Rps. sphaeroides (wild type) chromatophores, using lauryldimethylamine oxide (LDAO) as detergent, is described. The preparation obtained is free of a light-harvesting pigment-protein complex and cytochromes. A high degree of purity can be demonstrated from the adsorption indexes of the preparation equal to A280 : A800 = 1.2--1.3; A760 : A800 : A870 = 1 : 2 : 0.9. Data from polyacrylamide gel electrophoresis suggest that the integral protein component of the preparation is made up of three polypeptides with molecular weights of 30 000, 24 000 and 20 000. Under continuous illumination the preparation exhibits an effective electron transfer from the bacteriochlorophyll dimer (BChl)2 to a system of quinone acceptors (X1, X2). The ambient potential Em of (BChl)2 half-recovery was estimated as + 475 mV and pH 7.2. The rate constant for direct electron transfer from X1- to X2 is about 0.5 . 10(3) s-1 at 300 degrees K (0.01 M phosphate buffer; 0.05% LDAO, pH 7.2). The activity of this transfer is exponentially reduced with a decrease in temperature within the range of 300 to 230 degrees K, with an activation energy, Ea, of approximately equal to 8 kcal. The recombination rate constant of light-induced ion-radicals, (BChl)2+ and X1-, was found to be 5 . 10(-2) s-1 at 180 degrees K. The preparations thus obtained can be used for studying mechanisms of primary events in photosynthesis and electron-exchange conformations in the reaction center.

Bacterial Proteins↗
PubMed1981

[Metabolic activation and the mutagenic properties of carcinogenic N-nitramines in a liquid incubation test].

The study established the mutagenicity of carcinogenic dimethylnitramine and nitromorpholine in a liquid-incubation system using Salmonella typhimurium TA 100 and TA 1530 as indicator, in the presence of hepatic postmitochondrial supernatant obtained from 1254 aroclor-treated rats, oxygen and NADP+--generating system. Synthesis of mutagenic metabolites of nitramines was in correlation with the level of N-dimethylase activity. Ascorbic acid and disulfiram efficiently inhibited intramune-induced mutagenesis. Metabolic activation of nitramines involves (a) conversion of nitramines to nitrosoamines due to reduction of a nitro group, (b) hydroxylation by means of multi-function oxydases, and (c) heterolysis resulting in the formation of an end metabolite which is actually responsible for carcinogenicity and mutagenicity.

Aniline Compounds↗
PubMed1995

Effects of repeated oral doses of Dikamin D (2,4-D-amine Na) on rats.

The toxic effects of repeated, increasing oral doses of Dikamin D (72% 2,4-D-amine Na), a broad leave herbicide product used world-wide, were evaluated on rats by the method of Lim et al. (1961). A comparison of the determined acute oral LD50 and the calculated subchronic oral LD50 values revealed a definite tolerance of the experimental animals to the test compound. This finding indicates that repeated oral treatment is capable of increasing the test animal's metabolizing capacity, which accounts for the development of tolerance.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1993

[The dependence of the nitrosation activity of the gastric juice in humans on their age and the type of pathological status of the gastric mucosa].

The study involved two groups of patients aged 6-14 and 40-60 years, and identification of different conditions of gastric mucosa. The study has established a correlation between the nitrosation activity and acidity of gastric juice and the pathological condition of the gastric mucosa. Enhanced nitrosation activity was observed in samples with a pH under 4.0. That activity was at its lowest in cases of normal gastric mucosa, and at its peak--in high-acidity superficial and erosive gastritis. In cases of superficial gastritis with similar levels of acidity, the nitrosation activity of gastric juice for different amines in children was 2-4 times that in adults. The difference in nitrosation levels for different amines tended to diminish with the decrease in the basicity of the amine in question. A linear correlation was observed between the free-radical activity of gastric juice samples and nitrosation activity (correlation coefficient, k = 0.72).

Adolescent↗
PubMed1993

Detergent binding as a measure of hydrophobic surface area of integral membrane proteins.

The mode by which four nonionic detergents interact with integral membrane proteins was studied by relating detergent binding to characteristic detergent monolayer and micellar dimensions and to the surface area of the hydrophobic sector of the proteins. The detergents used (C12E8, Triton X-100, dodecyl-beta-D-maltoside, and dodecyldimethylamineoxide) are efficient membrane solubilizers, which, according to our hydrodynamic analysis, form small approximately spherical micelles. Their binding by protomeric forms of bacteriorhodopsin, photosynthetic reaction center, sarcoplasmic reticulum Ca(2+)-ATPase, and cytochrome oxidase was measured after equilibration and delipidation, both by the use of successive chromatographies on silica gel and the use of agarose gel columns in combination with DEAE-cellulose chromatography. It was found that, despite detergent binding by silica gel, both chromatographic procedures gave equivalent and consistent results. The data obtained show systematic trends; thus dodecyldimethylamineoxide exhibited the highest binding levels, followed by dodecylmaltoside, whereas the polyethylene glycol detergents C12E8 and Triton X-100 had the lowest degree of binding. This ranking order is inversely related to the cross-sectional areas of these detergents in monolayers at an air-water interface and in micelles. Binding was reduced by aggregation of protomers, whereas the presence of strongly bound residual lipid slightly increased it. Among the membrane proteins with a high molecular mass (reaction center, Ca(2+)-ATPase, and cytochrome oxidase), relative binding could be related to the size of their hydrophobic sectors. On the other hand, bacteriorhodopsin bound somewhat more detergent per transmembrane helix, probably because of less steric hindrance, caused by the absence of a sizable hydrophilic domain in this protein. Theoretical calculations indicated monolayer binding of detergent to the hydrophobic surface of membrane proteins to be a better model for interaction with membrane proteins than binding of the detergents in micellar form.

Animals↗
PubMedDate not supplied

The functional affinity and specificity of autoantibodies in animal models of anti-glomerular basement membrane disease.

We studied characteristics of the anti-glomerular basement membrane (GBM) antibody response in three animal models of Goodpasture's disease: treatment of Brown Norway (BN) rats with the polyclonal activator mercuric chloride (HgCl2), and immunization of BN and Wistar Kyoto (WKY) rats with rat GBM. Serial serum samples were obtained over the time course of the models, and anti-GBM antibodies eluted from the kidneys. Functional affinity of the anti-GBM antibodies was measured in a solid-phase ELISA incorporating the mild chaotropic agent diethylamine. Evidence for shared epitope specificity with human anti-GBM antibodies was sought using competition ELISA. As with recent studies in human anti-GBM disease, there was no evidence for affinity maturation of the anti-GBM response in the serum of any of the animal models. Antibodies eluted from the kidneys were of higher functional affinity than serum antibodies only in the HgCl2-treated BN rat. There was no obvious correlation between the functional affinity of the antibodies and the severity of nephritis in the three models. Competition studies between eluted anti-GBM antibodies from the rat models and human anti-GBM antibodies did not provide any evidence for shared epitope recognition. This study provides further information on the extent to which these models reflect the human disease.

Animals↗
PubMed1996

Immunomodulatory effect of some amphiphilic detergents on the human promyelocytic HL-60 cells.

The effect of two anionic (sodium dodecyl sulfate (SDS) and sodium laurate), two cationic (didodecyldimethylammonium bromide (DDAB) and [(1-methyldodecyl)-trimethylammonium bromide (2-ATDBr)] and a nonionic [(1-methyldodecyl)-dimethyl-amine N-oxide (2-ATDNO)] amphiphilic detergents on the metabolic activation of phagocytes derived from human promyelocytic leukemia cell line HL-60 was investigated. SDS in the concentrations of 10(-4) M significantly stimulated the INT-reduction and superoxide production by HL-60 cells which were preincubated with phorbol 12-myristate 13-acetate (PMA) for a macrophage-like differentiation. This effect was not significant in the case of cells differentiated along monocyte-like and granulocyte-like pathways. A similar influence was observed by sodium laurate, but this effect was significant (P < 0.01) by INT-reduction only. Concentrations higher than 5 x 10(-5) M DDAB, 2-ATDBr and 2-ATDNO inhibited INT-reduction and superoxide generation in HL-60 cells differentiated along all three ways. Our results indicated that differentiated HL-60 cells may be used for in vitro testing of immunotoxic effects on respiratory burst in phagocytes.

Detergents↗
PubMed1996

[Effect of n-nitrosodimethylamine (NDMA) on activity of selected enzymes in blood serum of the rat].

Changes in the activity of GOT, GPT, AP and GGTP in blood of rats intoxicated by low doses of N-Nitrosodimethylamine (NDMA) are presented. A significant increase in the activity of GOT and GPT was found after single doses (20 micrograms/kg b.w.) of NDMA as well as a significant increase in the activity of GOT, GPT, AP and GGTP after a prolonged intoxication per os by doses of 20 micrograms/dm3 given in drinking water.

Administration, Oral↗