桑寄生的遗传毒理学研究

目的探讨桑寄生水煎液对成年小鼠及胚胎鼠的遗传毒性。方法采用小鼠急毒试验、小鼠骨髓嗜多染红细胞微核试验、小鼠胚胎肝转移微核试验、小鼠精子畸形试验。结果桑寄生水煎液急毒试验为无毒级,最大用药剂量为40g/kg。桑寄生水煎液灌胃孕鼠和雄鼠40g/kg剂组诱发的胚胎肝微核率、骨髓微核率、精子畸形率均较阴性对照组显著升高（P〈0.05）。桑寄生灌胃剂量为20g/kg时,诱发的胚胎肝微核率较阴性对照组显著升高（P〈0.05）,骨髓微核率与精子畸形率与阴性对照组相比,无显著性差异（P〉0.05）。而10g/kg剂量组诱发的胚胎肝微核率、骨髓微核率、精子畸形率与阴性对照组相比,均无显著性差异（P〉0.05）。结论桑寄生水煎液40g/kg剂量组对成年小鼠和胎鼠均具有潜在的遗传毒性,20g/kg剂量组仅对胎鼠有潜在的遗传毒性,10g/kg剂量组对成年小鼠和胎鼠均无遗传毒性。     

罗汉果对雄性小鼠骨髓微核和精子形态的影响

背景：对罗汉果的遗传毒性进行研究,可为其安全使用提供实验依据。 目的：观察罗汉果水提液对雄性小鼠骨髓细胞微核率和附睾精子畸形率的影响,了解其是否有遗传毒性。 方法：按罗汉果水提液最大使用剂量(3 g/mL)和最大灌胃容量(20 mL/kg)灌胃小鼠,观察罗汉果水提液的急性毒性。将雄性昆明小鼠随机分为5组,分别灌胃给予30,15,7.5 g/kg的罗汉果水煎液、蒸馏水,连续5 d;或腹腔注射40 mg/kg环磷酰胺。于灌胃第5天,采用骨髓嗜多染红细胞微核试验计算小鼠的骨髓微核率。于首次灌胃后第35天,观察小鼠精子畸形率。 结果与结论：罗汉果水提液对昆明小鼠的经口急性毒性最大耐受剂量大于120 g/kg。罗汉果水提液30,15,7.5 g/kg灌胃后,小鼠的骨髓微核率、精子畸形率与正常小鼠无差异(P > 0.05),均明显低于环磷酰胺诱发的骨髓微核率和精子畸形率(P < 0.05)。说明罗汉果水提液对成年雄性小鼠无明显遗传毒性。     

氟西汀对雄性小鼠的遗传毒性研究

目的探讨氟西汀对成年雄性小鼠的遗传毒性。方法采用小鼠急毒试验、小鼠精子畸形试验、小鼠骨髓微核试验及生殖、淋巴器官重量指数分析方法。结果氟西汀对小鼠经1：2最大耐受剂量为15g／kg微核试验与精子畸形试验的小鼠均分6组,即氟西汀1.25mg／kg,2.5mg／kg,5mg／kg和10mg／kg4个剂量组与阴、阳性对照组其中灌胃剂量为1.25mg／kg、2.5mg／kg、5mg／kg时,均未诱发各组的精子畸形率、骨髓微核率增高,与阴性对照组相比均无显著差异（P〉0.05）;当剂量达到10g／kg时诱发的精子畸形率、骨髓微核率均略高于阴性对照组但有显著性差异（P〈O.05）;灌胃氟西汀各剂量组小鼠的生殖与淋巴器官重量指数与阴性对照组相比无显著变化（P＞O.05）。结论经口最大给药剂量为15g／kg,属于无毒级。氟西汀以1.25mg／kg、2.5mg／kg、5mg／kg的剂量灌胃小鼠无生殖与遗传毒性,当灌胃剂量达到30g／kg时,则对雄性小鼠有轻微的潜在遗传毒性。     

罗汉果甜甙对雄性小鼠的遗传毒性研究

目的探讨罗汉果甜甙对成年雄性小鼠的遗传毒性。方法采用小鼠急毒试验、小鼠精子畸形试验、小鼠骨髓微核试验及生殖、淋巴器官重量指数分析方法。结果罗汉果甜甙对小鼠经口最大耐受剂量为15异／kg。微核试验与精子畸形试验的小鼠均分6组，即罗汉果甜甙0．25g／kg、0．5g,／kg、1g/kg、5g／kg4个剂量组与阴、阳性对照组。其中灌胃剂量为0．25g/kg、0．5g／kg、1g／k时，均来诱发各组的精子畸形率、骨髓微核率增高，与阴性对照组相比均无显著差异（P〉0．05）：当剂量达到5g／kg时诱发的精子畸形率、骨髓微核率均略高于阴性对照组但有显著性差异（P〈0．05）。灌胃罗汉果甜甙各剂量组小鼠的生殖与淋巴器官重量指数与阴性对照组相比无显著变化（P〉0．05）。结论经口最大给药剂量为15g／kg，属于无毒级。罗汉果甜甙以0．25g／kg，0．5g／kg及1g/kg的剂量灌胃小鼠无生殖与遗传毒性。当灌胃剂量达到5g／奴时，则对雄性小鼠有轻微的潜在遗传毒性。     

柠檬黄对雄性小鼠生殖细胞的影响

探讨柠檬黄对雄性小鼠生殖细胞的影响.选择成年雄性小鼠分别给予柠檬黄0.25 g/kg(低剂量组)、0.5 g/kg(中剂量组)和1 g/kg(高剂量组),连续灌胃染毒5d,通过小鼠精子畸形率、精细胞微核率以及睾丸形态变化等方面来评价柠檬黄对生殖细胞的影响.与对照组相比,高剂量组的柠檬黄能引起小鼠精子的畸形率和精细胞微核...     

柠檬黄对雄性小鼠生殖细胞的影响

探讨柠檬黄对雄性小鼠生殖细胞的影响。选择成年雄性小鼠分别给予柠檬黄0.25 g/kg（低剂量组）、0.5 g/kg（中剂量组）和1 g/kg（高剂量组）,连续灌胃染毒5 d,通过小鼠精子畸形率、精细胞微核率以及睾丸形态变化等方面来评价柠檬黄对生殖细胞的影响。与对照组相比,高剂量组的柠檬黄能引起小鼠精子的畸形率和精细胞微核率升高（P〈0.05）,而中、低剂量组没有明显的变化（P〉0.05）。睾丸组织切片显示,低、中剂量组与对照组相比没有明显改变,高剂量组小鼠睾丸生精小管管腔内可见精子数量减少,生精上皮细胞层次减少,部分细胞有浓缩、溶解等坏死样变。高浓度的柠檬黄能使雄性小鼠精子畸形率增加,并造成雄性小鼠精细胞微核率上升,有一定的致突变性。     

烟草提取液诱导小鼠骨髓嗜多染红细胞微核的研究

目的 研究烟草提取液对小鼠骨髓嗜多染红细胞的遗传毒性效应.方法 采用30h给受试物法,用不同浓度烟草提取液灌喂实验小鼠,小鼠处死后检测小鼠骨髓嗜多染红细胞微核率.其微核率与环磷酰胺阳性对照组以及生理盐水阴性对照组嗜多染红细胞微核率比较其差异性.结果 发现不同浓度烟草提取液均可诱导小鼠骨髓嗜多染红细胞产生微核,其微核率与阳性对照组比较无显著差异,而远高于阴性对照组.结论 烟草提取液具有较大的遗传毒性.     

不同光照制对雄性小鼠生殖影响的研究

目的 探讨不同光照制对雄性小鼠生殖的影响。方法 取昆明种雄性小鼠作短期持续光照、持续黑暗、反相光照3种光照制处理。观察小鼠睾丸、附睾重量及光镜下睾丸、附睾组织学变化、精子数量、精子活动度、精子畸形率。结果 各组小鼠睾丸、附睾重量无显著性差异,而且各实验组光镜下睾丸、附睾组织学均未见异常。与对照组相比,黑暗小鼠和反相光照组小鼠精子数量明显降低,此外,反相光照组小鼠精子畸形率显著增加。结论 异常光照周期可能影响雄性小鼠生殖能力。     

衰老对小鼠精子成熟和受精能力的影响

目的：探讨衰老对附睾精子成熟、体外受精和胚胎发育的影响。方法： 取老龄小鼠（18月龄，n=15）和青年小鼠（6月龄，n=15）附睾头精子和附睾尾精子，分别检测精子密度、存活率、活动率、正常形态率和胞浆小滴率，并通过体外受精比较附睾尾精子受精率和各阶段胚胎发育率。结果：老龄小鼠附睾头精子和附睾尾精子活动率、精子密度显著低于青年组（P<0.01），胞浆小滴率和畸形精子率显著高于青年组（P<0.05），附睾尾精子的受精率下降（P<0.01），胚胎各阶段发育率降低（P<0.01）。结论：衰老影响小鼠精子功能及附睾精子成熟过程。小鼠可作为雄性生殖衰老研究的动物模型。     

金银花的食品安全性毒理学评价研究

本文报道金银花的食品安全性毒理学评价(一、二阶段)。结果 小鼠经口LD50>15g/kgBw,属无毒级。小鼠骨髓嗜多染红细胞微核实验和鼠沙门氏菌/哺乳动物微粒体酶实验表明无致突变作用。小鼠精子畸变实验表明对雄性动物生殖细胞无遗传毒性。SD大鼠抗早孕实验(经口)证明对雌性动物的孕期生殖功能无不良影响。     

Comparative mutagenicity of 2-methylpropene (isobutene), its epoxide 2-methyl-1, 2-epoxypropane and propylene oxide in the in vitro micronucleus test using human lymphocytes

2-Methylpropene (isobutene), a gaseous compound widely usedin chemical industries, is metabolized to the epoxide 2-methyl-1,2-epoxypropane. The parent compound has previously been shownto be non-mutagenic in a modified Ames test, whereas the epoxidemetabolite gave a positive result. In this study, both compoundshave been tested in the in vitro micronucleus test using humanlymphocytes. Propylene oxide, a well known mutagenic compound,served as a positive control. It was found that 2-methylpropenehad no mutagenic effect, whereas its epoxide induced a statisticallysignificant dose-dependent increase in the number of micronuclei.The effect observed was comparable with that obtained for propyleneoxide.     

Induction of micronuclei in bone marrow and sperm head abnormalities after combined exposure of mice to low doses of X-rays and acrylamide

People come into contact with chemical and physical agents which are present in the environment and in workplaces. We investigated the effects of combined exposures to low doses of X-rays (0.05-0.25 Gy) and acrylamide (AA; 75 mg/kg bw) in the somatic and germ cells of outbred male mice by using a bone-marrow micronucleus test and a sperm morphology test. Combined treatment of germ cells to 0.25 Gy of X-rays + 75 mg/kg bw of acrylamide enhanced the effect induced by each agent given alone. The results confirmed the sensitivity to damage of spermatozoa and late spermatids, which can be demonstrated by sperm head abnormalities and reduced fertility. The sensitivity of somatic cells to acrylamide alone was similar to that of germ cells. Combined exposure to 0.05 Gy + 75 mg/kg bw of AA induced micronuclei in polychromatic erythrocytes of bone marrow although each dose did not produce a mutagenic effect. Teratogenesis Carcinog. Mutagen. 20:133-140, 2000.     

Genotoxicity of surface water treated with different disinfectants using in situ plant tests

Disinfection of surface drinking water, in particular water chlorination, results in many by-products with potential genotoxic and/or carcinogenic activity. In the present study, we evaluated the genotoxicity of surface water after treatment with different disinfectants by means of in situ plant genotoxicity assays (micronucleus and chromosomal aberration tests) which can detect both clastogenic and aneugenic effects. The study was carried out at a pilot plant using lake water after sedimentation and filtration. This water supplied four stainless steel basins: three basins were disinfected with sodium hypochlorite, chlorine dioxide, and peracetic acid and the fourth basin containing untreated lake water was used as a control. Plants were exposed in situ in the basins. The study was carried out using water collected in different seasons over a period of about 1 year in order to assess the treatments in different physical and chemical lake water conditions. The micronucleus test in root cells of Vicia faba (Vicia faba/MCN test) revealed genotoxicity in many samples of disinfected water. The micronucleus test in Tradescantia pollen cells and the chromosome aberration test in root cells of Allium cepa showed genotoxic effects only in some disinfected samples, but also revealed genotoxicity in raw water. The results of the study indicated that the Vicia faba/MCN test was the most sensitive plant assay for disinfected water and that peracetic acid disinfection produced similar or lower genotoxicity than sodium hypochlorite or chlorine dioxide treatment.     

A micromethod for the in vitro micronucleus assay.

A micromethod for the in vitro micronucleus assay was developed using L5178Y cells to enable the rapid screening of a large number of molecules. The method is quick, simple to perform and needs very small amounts of compound, i.e. <10 mg. In this methodology, three types of treatment were carried out in parallel, enabling an optimal detection of both aneugenic and clastogenic compounds: two treatments without metabolic activation with or without a recovery period after a 24 h continuous treatment and one treatment with metabolic activation by Aroclor 1254-induced rat or hamster liver S9 mix. Seventeen known genotoxins (12 clastogens and five aneugens) and seven known non-genotoxins were tested. The in vitro micronucleus micromethod using L5178Y cells exhibited good sensitivity (16 positive/17 known genotoxins tested) and specificity (7 negative/7 known non-genotoxins tested) for the 24 test compounds studied with or without metabolic activation. Furthermore, this test showed a good correlation with other in vitro micronucleus tests performed using macromethods with various mammalian cell cultures. We conclude that the in vitro micronucleus micromethod with L5178Y cells could be used in the earliest stages of development of new molecules as a preliminary short-term screening assay before starting regulatory tests.     

Trichlorfon induces spindle disturbances in V79 cells and aneuploidy in male mouse germ cells

In order to assess the effects of trichlorfon on cell division and on aneuploidy induction, we conducted an in vitro assay for spindle disturbances using V79 cells and an in vivo assay for aneuploidy induction in meiosis of male mice using multicolour fluorescence in situ hybridization (FISH) with epididymal sperm. In the in vitro assay, the chemical caused a concentration-dependent increase in the incidence of initial and full c-mitoses in the dose range 40-120 microg/ml trichlorfon. The mitotic index (MI) was decreased between 40 and 100 microg/ml trichlorfon, whereas at 120 microg/ml the MI was back to the control level, coinciding with the dramatic increase in c-mitoses. The results confirm that trichlorfon is a potent spindle poison in V79 cells. In the in vivo multicolour FISH assay, administration of trichlorfon to male mice at single doses of 200, 300 and 405 mg/kg caused a dose-dependent increase of the frequencies of disomic sperm (0.068, 0.074 and 0.134%, respectively) compared with the corresponding controls (0.046, 0.042 and 0.056%, respectively). The prevalence of X-X-8 and Y-Y-8 sperm suggests that trichlorfon affected chromosome segregation predominantly during the second meiotic division. Diploid sperm were not induced by trichlorfon treatment, indicating that no meiotic block occurred. It is concluded that trichlorfon is a potent spindle poison in V79 cells and induces aneuploidy in mouse spermatocytes during meiosis.     

Application of antikinetochore antibody staining (CREST staining) to micronuclei in erythrocytes induced in vivo

Micronuclei (MN) can be formed by acentric chromosome fragments or whole lagging chromosomes. In order to discriminate MN produced by chromosome breakage from those arising from spindle malfunction a staining method using immunofluorescent kinetochore antibodies has been applied successfully in vitro. In the present study MN in polychromatic erythrocytes of mouse bone marrow cells induced in vivo by the spindle poison colchicine (COL) and the clastogen mitomycin C (MMC) were analysed after CREST staining. The staining method was modified by using pretreatment with detergents in order to allow a good penetration of the antibodies into the MN. About 66% of the MN induced by COL in contrast to only 4.5% of the MMC induced MN were CREST-positive. The preliminary results show that the CREST staining is also in MN induced in vivo capable of detecting the origin of MN and to discriminate between the spindle damaging or clastogenic activity of environmental agents. The method described will give supplementary information about MN, it cannot substitute for the common micronucleus test.     

Mutagenic evaluation of nitroparaffins in the salmonella typhimurium/mammalian-microsome test and the micronucleus test

Three nitroparaffins (nitroethane, 1-nitropropane, and 2-nitropropane) were studied in the Salmonella typhimurium/mammalian microsome (Ames) test, with and without microsomal activation systems. Nitroethane and 2-nitropropane also were studied in an in vivo mutagenic (micronucleus) test. These studies were undertaken because these solvents are widely used in the chemical and pharmaceutical industries and 2-nitropropane was reported to cause liver cancer in rats exposed by the inhalation route. Neither nitroethane nor 1-nitropropane was active in the Ames test with Salmonella tester-strains TA1537, TA92, TA98, or TA100. However, 2-nitropropane produced a significant increase in revertants in all of these tester strains, particularly strain TA100, where 3μl/plate doubled the number of revertants in the presence of microsomal enzymes. Negative results were obtained with both nitroethane and 2-nitropropane in micronucleus tests. These studies have shown that 2-nitropropane has the potential for causing point mutations in a microbial test system. However, this compound probably will not cause a chromosome mutation of the clastogenic type.     

Mutagenic evaluation of nitroparaffins in the Salmonella typhimurium/mammalian-microsome test and the micronucleus test.

Three nitroparaffins (nitroethane, 1-nitropropane, and 2-nitropropane) were studied in the Salmonella typhimurium/mammalian microsome (Ames) test, with and without microsomal activation systems. Nitroethane and 2-nitropropane also were studied in an in vivo mutagenic (micronucleus) test. These studies were undertaken because these solvents are widely used in the chemical and pharmaceutical industries and 2-nitropropane was reported to cause liver cancer in rats exposed by the inhalation route. Neither nitroethane nor 1-nitropropane was active in the Ames test with Salmonella tester-strains TA1537, TA92, TA98, or TA100. However, 2-nitropropane produced a significant increase in revertants in all of these tester strains, particularly strain TA100, where 3 microliter/plate doubled the number of revertants in the presence of microsomal enzymes. Negative results were obtained with both nitroethane and 2-nitropropane in micronucleus tests. These studies have shown that 2-nitropropane has the potential for causing point mutations in a microbial test system. However, this compound probably will not cause a chromosome mutation of the clastogenic type.