人参皂苷Rb_3对中国仓鼠肺细胞染色体畸变作用

目的研究人参皂苷Rb3对中国仓鼠肺细胞（CHL）染色体畸变作用。方法测定人参皂苷Rb3对CHL细胞的半数抑制浓度（IC50）,根据IC50设立不同剂量组,进行染色体畸变试验,分别观察人参皂苷Rb3接触CHL细胞6 h、24 h及加S9后6 h染色体的畸变情况,根据标准进行结果判定。结果染毒6 h、24 h及加S9后染毒6 h染色体畸变为阴性。结论人参皂苷Rb3不能引起CHL细胞染色体产生畸变作用。     

高纯度大豆卵磷脂对中国仓鼠肺细胞染色体畸变作用

目的研究高纯度大豆卵磷脂对中国仓鼠肺细胞（cHL）染色体畸变作用。方法测定高纯度大豆卵磷脂对CHL细胞的半数抑制浓度（IC50）,根据IC50设立不同剂量组,进行正式试验,分别观察高纯度大豆卵磷脂接触CHL6h,24h及加S9后6h染色体的畸变情况,根据标准进行结果判定。结果染毒6h,24h及加S9后染毒6h染色体畸变为阴性。结论高纯度大豆卵磷脂不能引起CHL细胞染色体产生畸变作用。     

槲皮素对中国地鼠肺成纤维细胞、小鼠骨髓细胞和小鼠睾丸精母细胞染色体影响的初步研究

目的:研究槲皮素对中国地鼠肺成纤维细胞、小鼠骨髓细胞和小鼠睾丸精母细胞染色体的影响.方法:采用80、40、20、10、5μg/mL 5个剂量组的槲皮素在有或无代谢活化条件下处理体外培养的中国地鼠肺成纤维细胞(CHL)3小时后更换新鲜培养液,恢复生长21小时后收获细胞制片.体内试验以10000、5000、2500mg/kg剂量的槲皮素给ICR小鼠灌胃后取股骨骨髓、两侧睾丸进行制片.观察槲皮素对三种哺乳动物细胞染色体的影响.结果:在有或无代谢活化条件下槲皮素在浓度>10μg/mL均能够诱导CHL细胞染色体断裂和交换等,染色体细胞畸变率显著增加(P<0.01);而槲皮素各剂量组未引起小鼠骨髓细胞染色体断片、交换、畸变细胞率显著增加,亦未引起小鼠睾丸精母细胞染色体断片、易位、畸变细胞率、常染色体单价体、性染色体单价体显著增加.结论:在本试验条件下槲皮素对体外哺乳动物细胞显示出明显致突变性,存在潜在的遗传毒性,对体内哺乳动物体细胞及生殖细胞染色体无明显损伤作用.     

云南红豆杉中紫杉烷类二萜成分化合物的遗传毒性研究

目的:研究云南红豆杉中四种紫杉烷类二萜成分化合物(2-去乙酰氧基紫杉宁E、7-去乙酰氧基紫杉宁J、2-去乙酰氧基去肉桂酰基紫杉宁、巴宁亭酸)的安全性。方法:采用Alarmblue检测采用四种紫杉烷类二萜成分化合物在CHL细胞上的细胞毒性,采用CHL细胞染色体畸变实验和Ames试验,观察云南红豆杉中四种紫杉烷类二萜成分化合物遗传毒性作用。结果:四种紫杉烷类二萜成分化合物在CHL细胞株上IC500.5 mg/m L;未对鼠伤寒沙门氏杆菌组氨酸缺陷型菌株回复突变数产生影响;未使得CHL染色体畸变率增加。结论:在本实验条件下,未观察到2-去乙酰氧基紫杉宁E、7-去乙酰氧基紫杉宁J、2-去乙酰氧基去肉桂酰基紫杉宁、巴宁亭酸对CHL细胞有明显的细胞毒性以及未观察到体外遗传毒性。     

文蛤肉水解液的致突变性

目的评价文蛤肉水解液的致突变性,为文蛤的开发利用提供实验数据。方法采用Ames试验、小鼠嗜多染红细胞骨髓微核试验和CHL细胞体外染色体畸变试验3项致突变性试验,检测文蛤肉水解液有无致突变作用。结果 Ames试验中文蛤肉水解液各剂量组回变菌落数均在正常范围内,均未超过自发回变菌落数的2倍,在加与不加S9时5株试验菌株结果为阴性。CHL细胞体外染色体畸变试验,文蛤肉水解液各剂量组的染色体畸变率与阴性对照组比较,差异无显著性(P0.05),结果为阴性。小鼠骨髓微核试验,各剂量组的微核率与阴性对照组比较,差异无显著性(P0.05),结果为阴性。结论在本试验条件和范围下,文蛤肉水解液未见潜在的致突变作用。     

稀土元素钬对蚕豆的细胞毒性和遗传毒性研究

运用氧化钬与稀硝酸反应制备结晶,以去离子水溶解并且稀释成梯度溶液,对蚕豆根尖染毒6 h,分别修复培养22h和24h,观察根尖变化,统计微核率、染色体畸变率及有丝分裂指数。结果表明,4mg/L（以氧化钬质量体积浓度计）以下剂量对根尖生长具有促进作用;随着浓度的递增,微核率、染色体畸变率逐步上升,有丝分裂指数逐步下降,表现出明显的剂量-效应关系,说明稀土元素钬具有一定的细胞毒性和遗传毒性。同时,不同修复组在微核率、染色体畸变率及有丝分裂指数上也存在一定差异,表现为微核率22h修复组低于24 h 修复组,而染色体畸变率和分裂指数均高于24h修复组。微核检测应在染色体畸变检测之后进行。      

入侵植物香丝草水浸提液对蚕豆和玉米根尖染色体行为的影响

以采自农田中自然生长的植物群落中的香丝草为供体,以典型的双子叶植物蚕豆和典型的单子叶植物玉米的幼苗为受体,运用根尖微核试验和染色体畸变试验,研究了香丝草的根、茎、叶和幼果4种器官水浸提液对受体的遗传毒性。结果表明:(1)在香丝草不同器官水浸提液作用下,蚕豆和玉米根尖细胞的有丝分裂各时期均受到明显影响,细胞中出现了微核、染色体桥、染色体断片、染色体环、染色体粘连及染色体滞后等多种染色体畸变。(2)香丝草各器官水浸提液对蚕豆幼苗根尖细胞分裂的抑制作用明显大于玉米。(3)香丝草各器官水浸提液对蚕豆和玉米幼苗根尖的染色体畸变诱导存在显著的浓度效应,即水浸提液浓度越高,受体的微核率和畸变率越高,相应的有丝分裂指数越低,水浸提液的诱导作用与浓度呈正相关关系,但不是简单的加和作用。(4)香丝草各器官水浸提液均具有较强的遗传毒性,但整体化感效应表现为叶＞幼果＞茎＞根,即叶片产生的化感作用最强。因此,香丝草分泌的化感物质可能通过对受体植物生长点的细胞有丝分裂和细胞形态产生影响,造成受体植物染色体的多种畸变和不可逆的遗传损伤,从而成功入侵新的栖息地。     

乙酸铜对蚕豆根尖细胞致畸效应

采用蚕豆根尖细胞的微核试验和染色体畸变试验方法,以不同浓度的乙酸铜为诱变剂,选择不同的处理时间,测定蚕豆根尖细胞的有丝分裂指数、微核率和染色体畸变率。结果表明：乙酸铜能诱发较高频率的微核率,处理6h、12h时微核率均随着乙酸铜浓度的升高而增加,具有明显的剂量效应;处理24h时在实验浓度范围内,其微核率随乙酸铜浓度的升高而增加,但高于一定浓度后反而呈下降趋势。不同浓度的乙酸铜在不同处理时间均使蚕豆根尖细胞有丝分裂指数增大。乙酸铜还能诱导蚕豆根尖细胞产生较高频率的染色体畸变,且产生多种类型的染色体畸变。因此,乙酸铜对蚕豆根尖细胞具有明显的致畸效应。     

硫酸铜对蚕豆根尖细胞有丝分裂的影响

以蚕豆根尖为材料,研究硫酸铜对蚕豆根尖细胞的遗传毒性效应。采用蚕豆根尖细胞的微核试验方法和染色体畸变试验方法,以不同浓度的硫酸铜为诱变剂,测定蚕豆根尖细胞的有丝分裂指数、微核率和染色体畸变率。结果表明:不同浓度的硫酸铜均能使蚕豆根尖细胞有丝分裂指数明显增加,即5个实验组的分裂指数均明显高于对照组(P<0.01或P<0.001);不同浓度的硫酸铜对蚕豆根尖细胞有丝分裂各期百分数的影响有异;能诱发较高频率的微核率,即在一定浓度范围内,其微核率随硫酸铜处理浓度的升高而增加,但随着硫酸铜浓度的进一步升高而呈下降趋势;硫酸铜还能诱导染色体产生多种类型的畸变,染色体畸变率随硫酸铜处理浓度的升高而增加,随着硫酸铜浓度的进一步升高而呈下降趋势,但均明显高于对照组(P<0.001)。结论是硫酸铜对蚕豆根尖细胞具有明显的遗传毒性效应。     

除草剂精禾草克对黄鳝细胞遗传毒性的研究

采用红细胞微核和核异常、染色体数目和结构畸变的方法,研究了除草剂精禾草克对黄鳝细胞的遗传毒性。结果表明,不同浓度的精禾草克作用３０小时,红细胞微核细胞率没有明显变化,核异常细胞率和总核异常细胞率均有所上升,部分组与对照组差异显著。染色体数目畸变率均有所上升,有的组甚至与对照组差异级显著,染色体结构畸变率也显著上升,各组与对照差异显著或极显著。表明一定浓度范围内的精禾草克作用一定时间对黄鳝在明显的遗     

Evaluation of magnolia bark extract in chromosomal aberration assays

Magnolia bark extract (MBE) has been used historically in traditional Chinese and Japanese medicines, and more recently as a component of dietary supplements and cosmetic products. The genotoxic potential of MBE was studied in two in vitro chromosomal aberration assays. In Chinese hamster ovary (CHO) cells, exposure for 3 h to MBE at concentrations of 0-30 microg/ml in the absence of a metabolic activation system (S9) and 0-7 microg/ml with S9 did not induce chromosomal aberrations, whereas higher concentrations were cytotoxic and did not allow for analysis of aberrations. Extended exposure for 18 h without metabolic activation at concentrations up to 15 microg/ml also resulted in a negative response. In V79 cells derived from Chinese hamster lung tissue, treatment for 6h with concentrations up to 52 and 59 microg/ml in the absence and presence of S9, respectively, did not increase the incidence of chromosomal aberrations compared to negative controls. Furthermore, MBE exposure for 24 h without metabolic activation did not induce aberrations. The results of these studies demonstrate that MBE is not genotoxic under the conditions of the in vitro chromosomal aberration assays in CHO and V79 cells, and support the safety of MBE.     

An improved system for exposure of cultured mammalian cells to gaseous compounds in the chromosomal aberration assay

A gas exposure system using rotating vessels was improved for exposure of cultured mammalian cells to gaseous compounds in the chromosomal aberration assay. This system was composed of 12 square culture vessels, a device for preparation of air containing test gas, and positive and negative control gases at target concentrations and for supplying these gases to the culture vessels, and a roller apparatus in an incubator. Chinese hamster lung cells (CHL/IU) were grown on one side of the inner surface of the square culture vessel in the MEM medium. Immediately prior to exposure, the medium was changed to the modified MEM. Air in the culture vessel was replaced with air containing test gas, positive or negative control gas. Then, the culture vessels were rotated at 1.0 rpm. The monolayered culture cells were exposed to test gas during about 3/4 rotation at upper positions and alternatively immersed into the culture medium during about 1/4 rotation at lower positions. This system allowed the chromosomal aberration assay simultaneously at least at three different concentrations of a test gas together with positive and negative control gases with and without metabolic activations, and duplicate culture at each exposure concentration. Seven gaseous compounds, 1,3-butadiene, chlorodifluoromethane, ethyl chloride, methyl bromide, methyl chloride, propyne, and vinyl chloride, none of which has been tested to date, were tested on CHL/IU for the chromosomal aberration assay using this gas exposure system. All the compounds except chlorodifluoromethane showed positive responses of the structural chromosomal aberrations, whereas polyploidy was not induced by any of these gases. This improved gas exposure system proved to be useful for detecting chromosomal aberrations of gaseous compounds.     

An improved system for exposure of cultured mammalian cells to gaseous compounds in the chromosomal aberration assay

A gas exposure system using rotating vessels was improved for exposure of cultured mammalian cells to gaseous compounds in the chromosomal aberration assay. This system was composed of 12 square culture vessels, a device for preparation of air containing test gas, and positive and negative control gases at target concentrations and for supplying these gases to the culture vessels, and a roller apparatus in an incubator. Chinese hamster lung cells (CHL/IU) were grown on one side of the inner surface of the square culture vessel in the MEM medium. Immediately prior to exposure, the medium was changed to the modified MEM. Air in the culture vessel was replaced with air containing test gas, positive or negative control gas. Then, the culture vessels were rotated at 1.0 rpm. The monolayered culture cells were exposed to test gas during about 3/4 rotation at upper positions and alternatively immersed into the culture medium during about 1/4 rotation at lower positions. This system allowed the chromosomal aberration assay simultaneously at least at three different concentrations of a test gas together with positive and negative control gases with and without metabolic activations, and duplicate culture at each exposure concentration. Seven gaseous compounds, 1,3-butadiene, chlorodifluoromethane, ethyl chloride, methyl bromide, methyl chloride, propyne, and vinyl chloride, none of which has been tested to date, were tested on CHL/IU for the chromosomal aberration assay using this gas exposure system. All the compounds except chlorodifluoromethane showed positive responses of the structural chromosomal aberrations, whereas polyploidy was not induced by any of these gases. This improved gas exposure system proved to be useful for detecting chromosomal aberrations of gaseous compounds.     

Expression of simian virus 40 gene A affects tubulin stability.

The stability of tubulins present in crude extracts of untransformed BALB/c-3T3 mouse fibroblasts, Chinese hamster lung cells, and various of their simian virus 40 transformants was assessed by measurement of their individual colchicine-binding decay rates. In all cases studied the decays followed the kinetics of first-order reactions, and rates were reduced at low temperatures and by vinblastine sulfate. Under all assay conditions, including different temperatures and protein concentrations, tubulins of normal cells decayed considerably faster than those of simian virus 40-transformed cells. Experiments performed with a number of Chinese hamster lung cell clones transformed with temperature-sensitive simian virus 40 gene A mutants showed a clear correlation between increased tubulin stability and the expression of gene A function. These results suggest that it is T-antigen, the viral gene A product, that affects tubulin.     

Comparative analysis of the clastogenicity and cytotoxicity of airborne particulate matter generated during the fire at Schweizerhalle on November 1, 1986

Methanol extracts from 4 pairs of airconditioner filters (one fire-exposed and one control) from various locations (A, B, C and D) at various distances from the site of the fire were examined for their capacity to induce structural chromosomal aberrations and/or cytotoxicity in Chinese hamster V79 cells. Extracts from 2 additional sets of 3 filters which were exposed to urban air for 3 consecutive periods of 10 or 11 days some 4 months after the fire were also tested. Chromosomal aberrations were induced by all filter extracts from location B, as well as by an unused (non-exposed) filter, in a dose-dependent manner. Without the addition of metabolizing enzymes, aberrations were induced only at concentrations which caused more than 95% cell killing. This was not taken as an indication for clastogenic activity of the filter extracts, but was assumed to represent the chromosomal expression of metabolic changes in dying cells. Upon the addition of S9, chromosomal aberrations were induced at biologically relevant survival rates. Under metabolizing conditions, the ranking of the potential of the filter extracts from location B to induce chromosomal aberrations and to cause cell killing was identical. The remaining extracts (locations A, C and D) were therefore tested for cytotoxicity only. The toxicity data indicated that, of 3 pairs of filters, the fire-exposed one was not different from the control. Of the fourth pair (location B), the fire-exposed filter was 2.0-2.5 times more cytotoxic and clastogenic than the control. However, extracts of urban air-exposed filters from this location (exposed in March and April 1987) showed a large variation in toxicity and clastogenicity as well. One was clearly more active than the control (but less than the fire-exposed filter), while the other 2 were either somewhat more or less clastogenic than the control filter. In addition, 4 out of 5 filters from this location were more polluted (as indicated by cytotoxicity) than all the filters from the other locations, irrespective of whether they were fire-exposed or not. It is concluded that the results of this V79 cytotoxicity/clastogenicity test did not confirm the hypothesis that the fire at Schweizerhalle produced clastogenic material at quantities detectable under the conditions employed.     

Genotoxicity evaluation of sesamin and episesamin

Sesamin is a major lignan that is present in sesame seeds and oil. Sesamin is partially converted to its stereoisomer, episesamin, during the refining process of non-roasted sesame seed oil. We evaluated the genotoxicity of these substances through the following tests: a bacterial reverse mutation assay (Ames test), a chromosomal aberration test in cultured Chinese hamster lung cells (CHL/IU), a bone marrow micronucleus (MN) test in Crlj:CD1 (ICR) mice, and a comet assay using the liver of Sprague-Dawley (SD) rats. Episesamin showed negative results in the Ames test with and without S9 mix, in the in vitro chromosomal aberration test with and without S9 mix, and in the in vivo comet assay. Sesamin showed negative results in the Ames test with and without S9 mix. In the in vitro chromosomal aberration test, sesamin did not induce chromosomal aberrations in the absence of S9 mix, but induced structural abnormalities at cytotoxic concentrations in the presence of S9 mix. Oral administration of sesamin at doses up to 2.0g/kg did not cause a significant increase in either the percentage of micronucleated polychromatic erythrocytes in the in vivo bone marrow MN test or in the % DNA in the comet tails in the in vivo comet assay of liver cells. These findings indicate that sesamin does not damage DNA in vivo and that sesamin and episesamin have no genotoxic activity.     

Clastogenic and Mutagenic Actions of Active Species Generated in the 6-Hydroxydopamine/Oxygen Reaction: Effects of Scavengers of Active Oxygen, Iron, and Metal Chelating Agents

A pro-oxidant triphenol, 6-hydroxydopamine (6-OHDA), induced mutations in the Salmonella typhimurium TA104 tester strain (over the concentration range to 800/JM), and induced chromosomal aberrations in cultured Chinese hamster ovary (CHO) cells at lower concentrations (up to 90 μM). It was however only marginally mutagenic (up to cytotoxic levels of 200 μM) in the TA102 tester strain. Clastogenicity in the more sensitive CHO cell assay was mediated by activated oxygen. Superoxide dismutase decreased the incidence of chromosomal aberrations by 60% and catalase (or superoxide dismutase plus catalase) decreased the incidence to control levels. The clastogenicity of 6-OHDA was dependent upon unsequestered transition metal ions, since addition of EDTA plus desferoxamine decreased chromosomal aberrations by 90%. The simplest explanation of the data is that genotoxicity is mediated by active species generated in a Fenton-type reaction between 6-OHDA and H₂O₂ catalyzed by traces of metals in the medium.     

Cytogenetic effect of the anticancer drug epirubicin on Chinese hamster cell line in vitro

The present study demonstrated the cytogenetic effect of the anticancer drug epirubicin on cultures of Chinese hamster cell line in vitro. The cultures were exposed to the drug for 24 h at three final concentrations; 10, 20 and 40 microg/ml. All treatments were carried out in the absence of any exogenous metabolic activation system.The different types of structural chromosomal aberrations, including gaps, breaks, deletions and fragments were increased in epirubicin-treated cultures. This increase was dose dependent where there was a positive correlation between increased drug concentration and induction of structural chromosomal aberrations. Also, the numerical chromosomal aberrations, including hypodiploidy and hyperdiploidy, were increased significantly in epirubicin-treated cultures. Like structural aberrations, the increase of numerical chromosomal aberrations was also dose-dependent.The frequency of sister chromatid exchanges in cultures treated with epirubicin increased significantly and this increase was dose-dependent. On the other hand, the epirubicin significantly decreased the mitotic index in treated cultures of Chinese hamster cell line.     

Clastogenic effects of biosynthetic human growth hormone in Snell dwarf mice and CHO cells in vitro

Treatment of Snell dwarf mice with high concentrations of human growth hormone from pituitaries as well as of bacterial origin, significantly increased the frequencies of chromosomal aberrations in bone-marrow cells, as measured by the micronucleus test. In vitro treatment of Chinese hamster ovary (CHO) cells with the two types of hormone likewise induced structural chromosomal aberrations.     

Virus induced chromosomal abnormalities in Chinese hamster lung cell line and human peripheral blood leukocyte culture

Chinese hamster lung (CHL) cells were susceptible to Herpes Simplex type-1 and Chandipura viruses; which induced chromosomal abnormalities in these cells. Chromosomal changes induced in these cells were specific. The cells were refractory to measles virus and chromosomal abnormalities were not detected after inoculation of the virus. On the other hand human peripheral blood (HPB) leukocytes were susceptible to all the 3 viruses studied and exhibited chromosomal abnormalities upon infection. The aberrations induced in HPBL cultures were random. The results suggest that a virus could induce chromosomal changes only in susceptible cells. This is the first report of comparative in vitro study on chromosomes.