J. Moutschen

Cytogenetic and genetic effects of subchronic treatments with organophosphorus insecticides

Male mice (Q strain) received 5 days a week for 7 weeks drinking water containing dichlorvos (2 ppm), dimethoate (0.6 ppm), malathion (8 ppm), methylparathion (0.15 ppm), or trichlorfon (0.5 ppm). At the end of the treatment, no chromosome damage was observed in bone marrow cells, spermatogonia, and primary spermatocytes. Dominant lethal mutation assays were performed to investigate the pre- and postimplantation foetal lethality. Only negative results were obtained.

Absence of genetic and cytogenetic effects in mice treated by the organophosphorus insecticide parathion, its methyl analogue, and paraoxon

Male mice (Q strain) received a single i.p. injection of 3 organophosphorus compounds: ethylparathion (10 mg/kg), its methyl analogue (methylparathion, 10 mg/kg), or its phosphate derivative (ethylparaoxon, 0.3 mg/kg). The number of chromosome aberrations observed in bone marrow cells and spermatogonia, and the frequency of pre- and postimplantation foetal lethality obtained in a dominant lethal mutation assay, did not conclusively prove that the tested compounds produced a mutagenic effect.

Cytogenetic effects induced by organophosphorus pesticides in mouse spermatocytes

Male mice (Q strain) received a single i.p. injection of 14 organophosphorus compounds, including 11 insecticides, administered on separate occasions. After a recovery period of 10 to 15 days, the cytogenic effects were analyzed in primary spermatocytes at diakinesis-metaphase I corresponding to the treatment of A4-B type spermatogonia. At the highest tolerated dose, trimethylphosphate (1000 mg/kg), triethylphosphate (300 mg/kg), dichlorvos (10 mg/kg), methylparathion (10 mg/kg), ethylparathion (10 mg/kg), ethylparaoxon (0.3 mg/kg), fenitrothion (1000 mg/kg), methylbromophos (1000 mg/kg), ethylbromophos (1000 mg/kg), dimethoate (10 mg/kg), malathion (300 mg/kg), methylazinphos (1 mg/kg), ethylazinphos (1 mg/kg) and trichlorfon (100 mg/kg) did not produce chromosome damage.

Mutagenicity of atrazine in Schizosaccharomyces pombe lindner with and without metabolic activation by maize

Abstract The mutagenic activity of two preparations of the herbicide atrazine (pure and a commercial formulation) was tested on yeast Schizosaccharomyces pombe (ade 7-C8) with and without in vivo activation by maize. The mutagenicity was much higher after activation (S1 fraction). The commercial formulation showed far higher activity than the pure compound. The genotoxic efficiency of a maize chloroplastic fraction after activation was also much higher than that of the supernatant, suggesting a transformation of the promutagen into an active mutagen in the organelle.

Chromosome-breaking activity of extracts of the mushroom Paxillus involutus Fries ex Batsch.

Dry and presoaked seeds ofNigella damascena were treated with aqueous extracts of the mushroomPaxillus involutus. At the first mitosis after the onset of germination, metaphase chromosomes showed damage independent of the origin of the mushrooms. The damaging substance(s) is (are) thermostable. Except a few achromatic gaps, all the lesions observed are of the chromosome type, i.e. are induced at the pre-synthetic G1 stage.

Clastogenic effects of benzodiazepines in a Nigella damascena seed test

Abstract Nigella damascena seeds were treated (5 hr) with solutions of different benzodiazepines. Chromosome damage was observed at the first mitosis after the onset of germination. At doses ranging from 12.5 to 50 μg/ml, no effects could be detected with the following substances: bromazepam, oxazepam, medazepam, prazepam, clonazepam and camazepam. Nitrazepam was ineffective at doses of up to 250 μg/ml. At doses ranging from 12.5 to 50 μg/ml, the following substances showed a linear dose-effect relationship: lorazepam, flunitrazepam and chlordiazepoxide as well as diazepam to 250 μg/ml. A proportion of damage was localized to constrictions. After diazepam, some aneuploid cells were found which are presumed to have arisen from chromosome non-disjunction.

Evaluation of the mutagenic potential of four commercial mixtures of insecticides

Male mice (Q strain) were given a single ip injection at the maximum tolerated dose of one of four commercial mixtures of insecticides: Luxan Tue-Taons (150 g dimethoate and 150 g fenitrothion/litre), Metadipterex (210 g trichlorfon and 270 g methyldemeton/litre), Dynafos (155 g malathion, 60 g dichlorvos and 75 g carbaryl/litre) and Phosan Plus (95 g dimethoate, 100 g malathion and 100 g methoxychlor/litre). At the maximum tolerated doses, Luxan Tue-Taons (60 mg/kg), Metadipterex (15 mg/kg), Dynafos (50 mg/kg) and Phosan Plus (100 mg/kg) did not induce chromosome aberrations in bone-marrow cells, spermatogonia or primary spermatocytes of the mice. No evidence of potential genetic effects was obtained in a dominant lethal mutation assay.

In vivo mutagenicity evaluation of domperidone in Drosophila germ cells and rat bone marrow cells

Possible induction of chromosome aberrations and gene mutations by domperidone was studied in vivo respectively by a micronucleus test on female rats and a sex-linked recessive lethal test on Drosophila. In accordance with previous results all these studies revealed negative findings for domperidone so that it can be concluded that domperidone has no potential to induce chromosome aberrations and/or gene mutations.

Genetic and Cytogenetic Effects of Fenitrothion

Male mice (Q strain) were injected intraperitoneally with a high dose (i.e., 1 g/kg) of the organophosphorus insecticide Fenitrothion. No increase in the percentage of chromosome aberrations was observed in bone marrow cells and spermatogonia. A dominant lethal mutation assay did not show any enhancement of fetal mortality before or after implantation.

Clastogenic effects of methoxy-7-nitro-2-naphtho (2,1-b) furan (R7000) on Nigella damascena L.

Abstract Clastogenic effects of a nitronaphthorufan (R7000) were investigated after treatment of seeds (“dry” and 30–50 hr presoake) or root tip cells. Nitronaphthofuran concentrations ranged from 0.12 to 32 × 10 −5 M for seeds and 0.12 to 2 × 10 −5 for root tips. All stages of the mitotic cycle were found to be sensitive, with a maximum of clastogenicity in G 2 . Chromosome lesions were predominantly of the following types: chromosome deletions, double minutes and gaps (isoachromatic or achromatic). R7000 accumulated metaphases, but counteracted the coiling sbfect of colchicine. In contrast, R7000 had a drastic uncoiling effect preferentially at the centromeric regions. This uncoiling leads to centrometric impairment and, eventually, chromosome breaks. Some mechanism(s) of action of the compound are suggested.