Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Micronucleus Tests”

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 37 records · Page 2Linked to original sources
PubMed1984

Genotoxic effects of ethyl acrylate and methyl acrylate in the mouse evaluated by the micronucleus test.

The micronucleus test was used to study the mutagenic effects of ethyl acrylate and methyl acrylate. Investigated compounds were administered to Balb C male mice by i.p. injection in two doses, separated by a period of 24 h. Ethyl acrylate at doses of 225-1800 mg/kg, and methyl acrylate at doses of 37.5-300 mg/kg significantly induce chromosome damage resulting in micronuclei formation in bone marrow polychromatic erythrocytes. Both investigated compounds significantly decrease the ratio of polychromatic to normochromatic erythrocytes. Positive results provide evidence of clastogenic activity of ethyl acrylate and methyl acrylate.

Acrylates↗
PubMed1995

Evaluation of the micronucleus test in vitro using Chinese hamster cells: results of four chemicals weakly positive in the in vivo micronucleus test.

A rapid and simple procedure for the micronucleus test (MNT) in vitro using Chinese hamster ovary (CHO) cells was established in our laboratory. The assay is intended to quickly screen chromosomal aberrations in vitro within the framework of industrial genotoxicity studies. To test the sensitivity of the assay in the experiments described here, four substances, classified as noncarcinogens but reported as weak inducers of micronuclei (MN) in bone-marrow cells of mice, were evaluated in the MNT in vitro. Of the four compounds, ascorbic acid, phenol, and 2,6-diaminotoluene proved to be genotoxic in the MNT in vitro. Titanium dioxide, which could not be dissolved in the culture medium, did not induce MN. The MNT in vitro proved to be quick and relatively simple and to yield highly reproducible results when testing the four chemicals.

Animals↗
PubMed1989

Genotoxicity of air pollution in a non-ferrous metal foundry in three bacterial tests and a micronucleus test--a comparative study.

Acetone extracts of dusts and fumes collected at workplaces in a non-ferrous metal foundry exhibited genotoxic activity in all of the tests used. Of the compared tests, the Ames method is the most useful for preliminary screening detection of the genotoxic agents that are present in acetone extracts of dusts and fumes emitted at workplaces in a non-ferrous metal foundry.

Air Pollutants, Occupational↗
PubMedDate not supplied

Single versus multiple dosing in the micronucleus test: the summary of the fourth collaborative study by CSGMT/JEMS.MMS. Collaborative Study Group for the Micronucleus Test, the Mammalian Mutagenesis Study Group of the Environmental Mutagen Society, Japan (CSGMT/JEMS.MMS).

The effects of multiple dosing in the micronucleus test were studied by treating male CD-1 mice 1, 2, and 4 times i.p. with various doses of 11 chemicals and by sampling bone marrow cells 6, 24, 48, and/or 72 h after the final dosing. The chemicals used were 2-acetylaminofluorene (2-AAF), 1-beta-D-arabinofuranosylcytosine (ARA-C), 7,12-dimethylbenz[a]anthracene (DMBA), ethyl methanesulfonate (EMS), N-ethyl-N-nitrosourea (ENU), 6-mercaptopurine (6-MP), phenacetin (PHEN), 5-fluorouracil (5-FU), methotrexate (MTX), benzene (BEN), and potassium chromate (K2CrO4). MTX, an inhibitor of nucleotide synthesis, was a weak micronucleus inducer after single dosing, but clearly positive after multiple dosing. Although ARA-C, 5-FU, and 6-MP became positive after single dosing, the multiple dosing enhanced the effects of these base analogues. ENU, DMBA, and BEN, at some doses and sampling times, also showed increased responses by multiple dosing, but a severe trade-off occurred enhanced toxicity tended to reduce the bone marrow cells, especially at 4 dosings, making the examination of micronuclei difficult. PHEN showed the multiple-dosing effect after 2 doses, but the effect disappeared at quadruple dosing. No apparent multiple-dosing effects were observed with 2-AAF, EMS, and K2CrO4, which gave similar incidences of micronuclei after single and double dosing. The original double dosing and sampling 6 h after the second injection method of Schmid (1975) was less sensitive than the modified method, i.e., sampling 24 h after the second dosing. The latter regimen is recommended for the general screening for the following reasons. (1) It was the most sensitive protocol among those tested here and detected all test chemicals as clastogens. (2) Since bone marrow specimens were prepared at or near the steady state of micronuclei, one sampling covered most chemicals with different actions. (3) For chemicals having multiple-dosing effects the recommended regimen was better than the protocol using 4 doses, because specimens could be prepared before the suppression of the bone marrow became excessive. (4) Chemicals having no multiple-dosing effect showed similar incidences of micronuclei after single and double dosing. (5) Dose selection is easier than with more multiple dosing, because, e.g., 50, 25, and 12.5% of LD50 values determined on single dosing will usually be tolerated by test animals. The detection spectrum would become wider if specimens are also prepared 48 h after the second dosing for metabolic inhibitors, base analogues, and the other chemicals which might show delayed activities.

Animals↗
PubMed1985

Mutagenicity testing of ST-film with the Ames test, chromosome test in vitro and micronucleus test in female mice.

The mutagenicity of ST-film and its components polyoxyethylenenonylether (NP-10) and polyvinylalcohol (PVAL) were studied by a reverse mutation test in S. typhimurium (Ames test), a chromosome test in cultured Chinese hamster V 79 cells and a micronucleus test in female mice. The results obtained from these test systems were all negative. Thus, it may be concluded that ST-film is not mutagenic either in vitro or in vivo mutagenicity testing systems.

Animals↗
PubMed2003

Occupational genotoxicity risk evaluation through the comet assay and the micronucleus test.

The micronucleus (MN) test and the alkaline single cell gel or comet assay were applied to exfoliated cells of the buccal mucous in order to evaluate the genotoxic risk associated with occupational exposure of 10 storage battery renovation workers, and 10 car painters, with age matched controls, in Pelotas, RS, in southern Brazil. In the MN test, 2000 exfoliated buccal cells were analyzed for each individual, while 100 cells were examined in the comet assay. In the comet test, both comet tail length and a damage index were calculated. Highly significant effects of occupational exposure were found with both the MN test and the comet assay (P<0.001). The comet assay was found to be rapid, of simple visualization, and it is a sensitive technique for measuring and analyzing DNA damage in human cells.

Adult↗
PubMed1989

Use of newt larvae for in vivo genotoxicity testing of water: results on 19 compounds evaluated by the micronucleus test.

The micronucleus test using erythrocytes of Pleurodeles waltl larvae (Amphibian, Salamandridae) was used to detect the genotoxic activity of various substances. Most of them were known (or suspected) to be mutagenic or carcinogenic in mammals. Larvae were reared in water containing either a test chemical (experimental group) or in control water and the levels of micronucleated red blood cells (RBCs) compared between the two groups. Aroclor 1254, butylated hydroxyanisole, phenobarbital and 12-O-tetradecanoyl-phorbol-13-acetate produced negative results, while acridine orange, benzo[alpha]pyrene, epsilon-caprolactam, cyclophosphamide, diethyl sulphate, epichlorhydrin, ethidium bromide, ethyl methanesulphonate, ethylene dibromide (dibromoethane), N-ethyl-N'-nitro-N-nitrosoguanidine, N-ethyl-N-nitrosourea, hexamethylphosphoramide, 3-methyl cholanthrene, pyrene and o-toluidine gave positive responses. The results were compared with published data from other tests used to detect the clastogenic or mutagenic properties of chemicals. We suggest that the newt micronucleus test could be used to monitor aquatic pollution, and/or for the quality control of drinking water. Pleurodele larvae may also prove to be of value for the detection of carcinogenic/clastogenic substances dissolved in water.

Animals↗
PubMed1991

Investigation of soy sauce treated with nitrite in the chromosomal aberration test in vitro and the micronucleus test in vivo.

Soy sauce pretreated with 2300 ppm nitrite caused no more aberrations than did untreated soy sauce in the chromosomal aberration test in vitro using a Chinese hamster fibroblast cell line with or without S9 mixture. The aberration induction by soy sauce is likely to be caused by the 17% sodium chloride it contains. Soy sauce with or without pretreatment with 2300 ppm nitrite was orally given to ICR mice at a dose of 14 ml/kg body weight once or 6 ml/kg body weight/day for 5 consecutive days. This oral administration did not induce any significant increase in micronuclei in the micronucleus test in vivo.

Animals↗
PubMed2003

Investigating genotoxic and hematotoxic effects of N-nitrosodimethylamine, N-nitrosodiethylamine and N-nitrosodiethanolamine in the hen's egg-micronucleus test (HET-MN).

The hen's egg test for micronucleus induction (HET-MN) combines the use of the commonly accepted genetic endpoint "formation of micronuclei" with the well-characterized and complex model of the incubated hen's egg, which enables metabolic activation, elimination and excretion of xenobiotics including mutagens and promutagens and does not conflict with animal protection regulations and ethical aspects. N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) produced clearly positive, dose-dependent and reproducible results in this assay. NDMA revealed, in accordance with literature data, a much higher mutagenicity than NDEA. For both compounds the sensitivity of HETMN was to a large extent higher than published for the rodent micronucleus test, which is not capable of unequivocally identifying NDEA as positive. Additionally, NDEA induced severe anemia without obscuring the formation of micronucleated cells. N-nitrosodiethanolamine (NDELA), which in the literature is described as a non-mutagenic animal carcinogen, could clearly be confirmed as non-mutagenic in the HETMN without showing any disturbing effects on the formation of erythrocytes. The micronucleus frequencies of the concurrent negative controls of all experiments was in agreement with the historic negative control from 302 eggs and 412,532 cells. The same is true for the historic control of proliferation marker from 61 eggs and 13,020 cells. We interpret these results, which correspond well to published data from animal tests, as being further support for using the HET-MN as a reliable alternative genotoxicity assay system, which is physiologically closer to in vivo conditions than in vitro genotoxicity tests, and allows the observation of further local and systemic effects.

Animals↗
PubMed1979

Mutagenicity tests of diflubenzuron in the micronucleus test in mice, the L5178Y mouse lymphoma forward mutation assay, and the Ames Salmonella reverse mutation test.

Diflubenzuron, one of a new class of pesticides believed to act via inhibition of chitin synthesis in the developing insect cuticle, was tested for possible mutagenic activity using the micronucleus test in mice, the L5178Y mouse lymphoma forward mutation test at the thymidine kinase locus, and the Ames Salmonella/microsome reverse mutation test. No mutagenic effect was found.

Animals↗
PubMed1980

The micronucleus test as part of a short-term mutagenicity test program for the prediction of carcinogenicity evaluated by 143 agents tested.

To evaluate the usefulness of the micronucleus test as a short-term assay for the detection of carcinogens, the correlation between micronucleus test data for 143 chemicals and corresponding cancer data, has been analyzed. For comparison, analogous data from Ames's test have also been collected for the same chemicals. In a comparison of the micronucleus test and Ames's test it was found that they had about the same specificity (around 80%) and predictive value (around 90%), while there was a significant difference in sensitivity in favor of Ames's test. The difference in sensitivity could be partly explained by differences in metabolizing capacities of these two test systems. It is concluded that a more elaborate test procedure for the micronucleus test would increase that sensitivity of this test. The principal value of the micronucleus test lies in the fact that it is an in vivo method, which may pick up effects at the chromosomal level not covered by bacterial assays. This is emphasized by the finding that the combination of Ames's test and the micronucleus test did increase the sensitivity of the screening procedure for the prediction of carcinogenic effects.

Animals↗
PubMed1992

Sampling times in micronucleus testing.

A series of micronucleus inducers were evaluated in the mouse bone marrow micronucleus test to determine if a 72-h sampling time enhances the sensitivity for detecting genotoxic agents. Male and female Swiss albino mice were dosed once with 7,12- dimethylbenz[a]anthracene, 6-mercaptopurine, benzo[a]pyrene, benzene, cyclophosphamide, 2-acetylaminofluorene, tubulazole, or mitomycin C. According to the EEC and OECD guidelines, the mice were killed at 24, 48 and 72 h after dosing. All test compounds induced an increase in the number of micronucleated polychromatic erythrocytes at 24 and/or 48 h. From the results obtained, it was evident that the 72-h sampling time does not enhance the sensitivity of the micronucleus test. The present data show that for screening purposes two sampling times at 24 and 48 h are sufficient to detect clastogens as well as aneugens. Although quantitative differences were found in sensitivity to micronucleus inducers between male and female mice, no qualitative differences were observed between the two sexes.

Animals↗
PubMed1984

Effects of vitamin A on cyclophosphamide mutagenicity in vitro (Ames test) and in vivo (mouse micronucleus test).

The effect of vitamin A on cyclophosphamide mutagenicity was measured both in vitro and in vivo. In the Ames test in Salmonella typhimurium TA1535 with mouse-liver S-9 mix, the addition of retinol, retinyl acetate or retinyl palmitate caused a dose-dependent inhibition of cyclophosphamide mutagenicity. In the micronucleus test in male NMRI mice fed low, normal or high levels of vitamin A, the induction of micronuclei in bone marrow by an ip dose of cyclophosphamide was unaffected by vitamin A status. Thus, this study provides no evidence that activation of a procarcinogen in the liver or bone marrow of mice can be modified by vitamin A. One of the possible reasons for the observed absence of inhibition by vitamin A in vivo may be a lack of correlation between the oral dose of retinoid and the resulting level of vitamin A in the bone marrow. The difference between results in vitro and in vivo may also have been due to a difference in the availability and potency of added vitamin A in vitro compared with the forms absorbed and stored in vivo.

Animals↗
PubMed1999

Assessment of the utility of the micronucleus test for petroleum-derived materials.

The micronucleus test is a commonly used in vivo assay for chromosomal damage and is an integral part of many mutagenicity testing strategies. The present report describes an assessment of the micronucleus test for the detection of mutagenic potential of petroleum-derived materials. To this end, studies were conducted with catalytically cracked clarified oil (CCCO). This material contains high levels of polycyclic aromatic constituents (PAC) and is a very potent inducer of mouse skin tumors. CCCO is also active in the Salmonella assay and other in vitro tests. As CCCO is the most potent of the various petroleum-derived materials in other assays, it was assumed to be the most easily detectable in the micronucleus test. CCCO was tested in standard mouse micronucleus tests utilizing oral and intraperitoneal injection for test material administration. All of these studies were negative, although DMBA, tested at roughly equivalent levels based on potency in the Salmonella assay, produced statistically significant increases in micronucleus frequency. In a second series of studies, aromatic fractions of CCCO were prepared and tested at up to acutely toxic levels. Results of these studies were also negative. Finally, another petroleum-derived material which is carcinogenic and contained PAC was tested in the micronucleus assay. It also produced negative results. Thus, it was concluded that petroleum-derived materials do not produce clastogenic effects in vivo in the mouse micronucleus test, despite the fact that some pure polycyclic aromatic hydrocarbons are quite active in this assay.

Animals↗
PubMed2006

A phytotherapeutic extract of Equisetum myriochaetum is not genotoxic either in the in vivo wing somatic test of Drosophila or in the in vitro human micronucleus test.

Equisetum myriochaetum is a Mexican plant used in folk medicine to treat kidney diseases and type 2 diabetes mellitus. The main constituents of the phytoextract are flavonol glycosides (kaempferol), phytoesterols and carbohydrates. In this study, phytotherapeutic extracts from Equisetum myriochaetum were investigated for genotoxicity in the in vivo wing spot test in Drosophila melanogaster and in the in vitro human micronucleus test. No acute toxicity of the phytoextract could be determined in Drosophila or in human lymphocytes in culture, ranging from 0.78 microg/ml to 3700 microg/ml for the wing assay and between 12.5 microg/ml and 500 microg/ml for the micronucleus test. The Drosophila wing somatic mutation and recombination test (SMART) was applied in the standard version with basal biotransformation activity as well as in a variant version with increased cytochrome P450-dependent bioactivation capacity. The ranges of exposure concentrations for these genotoxicity experiments were between 0.78 microg/ml and 500 microg/ml. The human micronucleus test in vitro was performed with cultured lymphocytes obtained from four healthy donors. The concentrations assayed for these experiments ranged from 12.5 microg/ml to 500 microg/ml. No statistically significant increase was observed between treated series when compared with a concurrent negative (water solvent) control series in either assay. The results demonstrate clearly that the phytotherapeutic extract from Equisetum myriochaetum, under the experimental conditions tested, is not genotoxic in the in vivo experiments or in the in vitro studies.

Adult↗
PubMed2005

Mutagenicity testing with transgenic mice. Part I: Comparison with the mouse bone marrow micronucleus test.

As part of a larger literature study on transgenic animals in mutagenicity testing, test results from the transgenic mutagenicity assays (lacI model; commercially available as the Big Blue(R) mouse, and the lacZ model; commercially available as the Mutatrade markMouse), were compared with the results on the same substances in the more traditional mouse bone marrow micronucleus test. 39 substances were found which had been tested in the micronucleus assay and in the above transgenic mouse systems. Although, the transgenic animal mutation assay is not directly comparable with the micronucleus test, because different genetic endpoints are examined: chromosome aberration versus gene mutation, the results for the majority of substances were in agreement. Both test systems, the transgenic mouse assay and the mouse bone marrow micronucleus test, have advantages and they complement each other. However, the transgenic animal assay has some distinct advantages over the micronucleus test: it is not restricted to one target organ and detects systemic as well as local mutagenic effects.

Journal Article↗
PubMed1998

Automatic analysis of the in vitro micronucleus test on V79 cells.

The in vitro micronucleus test is a well established test for early screening of new chemical entities in industrial toxicology. For assessing the clastogenic or aneugenic potential of a test compound, micronucleus induction in cells has been shown repeatedly to be a sensitive and specific parameter. As a measure for numerical and structural chromosome aberrations, the in vitro micronucleus test consists of determining the frequency of micronucleated cells in a representative fraction of cells in a culture. So far, manual counting has been the only method for evaluating microscopic V79 Chinese hamster cell preparations. To replace this tedious and time consuming procedure, a fully automatic system for micronucleus scoring in V79 cells by image analysis has been developed and introduced into the routine genotoxicity screening of drug candidates. The comparison of manual and automatic micronucleus analysis showed a high degree of concordance between the results obtained by the two techniques. For concentration series of cyclophosphamide (CP) and ethyl-methanesulphonate (EMS) as test compounds, the frequency of erroneously missed micronuclei through automatic scoring proved to be below 15% in comparison with manual scoring. Generally, false positive micronucleus decisions could be controlled easily by fast and simple relocation of the automatically detected patterns. The possibility to analyze 24 slides within 1 day by fully automatic overnight analysis and the high reproducibility of the results make automatic image processing a powerful tool for the in vitro micronucleus analysis.

Animals↗
PubMed1987

Mutagenic evaluation of etintidine (BL-5641), a novel histamine H2-receptor antagonist, using the chromosome aberration test in CHL cells and the micronucleus test in mice.

The mutagenic effects of etintidine (BL-5641), a novel histamine H2-receptor antagonist, was assessed using the chromosome aberration test in CHL cells and the micronucleus test in mice. (1) Etintidine did not show any chromosome aberrations in the presence or absence of S9 mix at any concentration tested. (2) Etintidine did not increase the frequency of micronuclei in polychromatic erythrocytes even at the dose of 50% of the LD50 at single (24 h) and chronological preparation after drug administration.

Animals↗