常见抗生素类兽药对作物的遗传毒性的研究

发布时间：2018-05-19 13:42

本文选题：抗生素类兽药 + 遗传毒性　；参考：《河南师范大学》2015年硕士论文

【摘要】：兽药是指用于预防、治疗动物疾病或有目的地调节动物生理机能的具有生物活性的化学物质。随着养殖业的迅速发展,兽药施用量大大增加,其作为饲料添加剂被用于养殖业中。其在动物体内并不能得到充分吸收,多以原药或代谢产物的形式随动物的排泄物进入环境,随食物链进入生态系统,对人体和环境的健康造成潜在危害。目前市场上最常见的兽药为磺胺类兽药,包括磺胺嘧啶,磺胺间甲氧嘧啶、磺胺甲恶唑等;喹诺酮类类兽药,如环丙沙星,氧氟沙星,诺氟沙星等;大环内酯类兽药,如红霉素、罗红霉素、阿奇霉素等。本研究选取了磺胺类、喹诺酮类、大环内酯类三种常见兽药作为实验对象,采用玉米、蚕豆、小麦三种作物作为实验材料,运用彗星、微核两种试验方法,研究所选兽药的遗传毒性作用。结果发现,磺胺类兽药可以在较低浓度明显诱发植物的遗传毒性作用,不同的作物对同一药物的敏感性不同。SD和SMM的处理下,3种作物的敏感性分别为:蚕豆玉米小麦;SMZ处理下,3种作物的敏感顺序为:蚕豆小麦玉米。磺胺类兽药复合污染条件下,单一兽药对作物的低促作用会消失;且低浓度磺胺类兽药的复合毒性高于单一毒性。SMM-SMZ复合表现出低浓度协同,高浓度拮抗作用。出现这种现象可能是因为SMM与SMZ的衍生基团处于苯环上同一位置,结构上相似导致两种兽药的作用机理相似。在染毒过程中,2种兽药在作物细胞染色体上的结合位点可能相同,故出现竞争机制。在低浓度作用下(1~10mg·L-1),结合位点尚未饱和,两种兽药分子均可与位点结合,对作物产生毒害加剧,相同浓度下SMM-SMZ复合比单一作用产生的微核率高,并在10mg·L-1时微核率达到最大值。随着浓度的继续升高至50~100mg·L-1,细胞DNA结合位点逐渐饱和,两种兽药分子因不能与DNA有效结合而无法产生更强的毒性作用。因此,SMM-SMZ复合作用高浓度下3种作物的微核率下降并趋于一致。喹诺酮类、大环内酯类兽药在较高浓度(100 mg·L-1)也可诱发作物的微核效应。喹诺酮类兽药可诱发3种作物的最大微核率浓度为600 mg·L-1,但其所诱发的最大微核率较低,平均最大微核率不超过22.64‰,3种不同种类喹诺酮类兽药对同种作物的微核率有显著影响,对3种作物的根尖细胞DNA损伤程度为蚕豆小麦玉米。且3种作物根尖细胞的受损程度随诺氟沙星溶液浓度的升高而增大。大环内酯类兽药400mg·L-1时可诱发作物的微核率达到最大值,且最大值的平均值23.31‰低于磺胺类兽药染毒下的最大微核率24.06‰,而高于喹诺酮类兽药诱发的平均最大微核率22.64‰,且能诱发最大微核率的兽药浓度为:磺胺类兽药低于大环内酯类兽药低于喹诺酮类兽药。同样浓度的红霉素与罗红霉素对作物根尖细胞DNA造成的损伤存在差异。由彗星细胞的拖尾率以及头尾部DNA含量的数据可知,红霉素、罗红霉素对3种作物根尖DNA损伤程度为蚕豆小麦玉米,但同样浓度下对于同种作物,罗红霉素对根尖细胞DNA的损伤大于红霉素综上,3种不同的抗生素类兽药均可在一定浓度下诱发作物根尖细胞的微核效应,但其遗传毒性之间存在区别,磺胺类兽药毒性最大,大环内酯次之,喹诺酮类类兽药毒性最弱。
[Abstract]:Veterinary drugs are bioactive chemicals used to prevent, treat animal diseases or regulate the physiological functions of animals. With the rapid development of the breeding industry, the amount of veterinary drugs is greatly increased. As a feed additive, it is used as a feed additive in the breeding industry. It is not fully absorbed in the animal body, mostly with the original or metabolic products. The most common veterinary drugs on the market are sulfadiazine, sulfadiazine, sulfamethoxazole, and other veterinary drugs such as ciprofloxacin, ofloxacin, norfloxacin, and so on. Macrolide drugs such as erythromycin, roxithromycin, azithromycin and so on. This study selected three common veterinary drugs such as sulfonamides, quinolones and macrolides as experimental objects, using three kinds of corn, broad bean and wheat as experimental materials, using comets and micronucleus two test methods to study the genetic toxicity of the selected veterinary drugs. It is found that sulfonamides can induce the genetic toxicity of plants at a lower concentration. The sensitivity of different crops to the same drug is different.SD and SMM, the sensitivity of the 3 crops is: broad bean corn wheat; under the SMZ treatment, the sensitive order of the 3 crops is: the broad bean wheat corn. The compound pollution condition of the sulfonamides. The low concentration of single veterinary drugs will disappear, and the compound toxicity of low concentration sulfonamides is higher than that of a single toxic.SMM-SMZ compound showing low concentration synergy and high concentration antagonism. This phenomenon may occur because the derivatives of SMM and SMZ are in the same position on the benzene ring, and the structure similarity leads to the effect of two kinds of veterinary drugs. The mechanism is similar. In the process of poisoning, the binding sites on the chromosomes of the 2 kinds of animal drugs may be the same, so there is a competition mechanism. Under the effect of low concentration (1~10mg. L-1), the binding site is not saturated, and the two kinds of veterinary drug molecules can be combined with the site, and the toxicity of the crops is aggravated, and the SMM-SMZ recombination at the same concentration is produced by the single action of the same concentration. The micronucleus rate was high and the micronucleus rate reached the maximum at 10mg L-1. As the concentration continued to rise to 50~100mg L-1, the DNA binding site of the cells gradually saturated, and the two kinds of veterinary drugs could not produce stronger toxic effects due to the failure to effectively combine with DNA. Therefore, the micronucleus rate of the 3 crops in the high concentration of SMM-SMZ compound decreased and tended to be consistent. Quinolones and macrolides can also induce micronucleus effects at a high concentration (100 mg. L-1). Quinolones can induce the maximum micronucleus rate of 600 mg. L-1 in 3 crops, but the maximum micronucleus rate is low and the average maximum micronucleus rate is not more than 22.64 per thousand. 3 kinds of different species of quinolones are made to the same species. The micronucleus rate of the 3 crops was significantly affected by the micronucleus rate of the 3 crops. The damage degree of the root tip cells of the 3 crops increased with the increase of the concentration of norfloxacin. The micronucleus rate of the macrolide 400mg L-1 could reach the maximum value of the crop, and the average value of the maximum value was less than 23.31 per thousand. The maximum micronucleus rate of sulfonamides was 24.06 per thousand, while the average maximum micronucleus rate induced by quinolones was 22.64 per thousand, and the concentration of veterinary drugs that could induce the maximum micronucleus rate was that the sulfonamides were lower than the macrolides in the quinolones. The same concentration of erythromycin and roxithromycin caused DNA in the root tip cells of crops. From the tail rate of comet cells and the data of the DNA content in the head and tail, it is known that erythromycin and roxithromycin damage the root tip DNA of 3 crops as the Vicia faba wheat corn, but under the same concentration, the damage of roxithromycin to the root tip cells DNA is larger than that of erythromycin, and 3 different antibiotic veterinary drugs are all in the same concentration. The micronucleus effect of the root tip cells of crop can be induced at a certain concentration, but there is a difference between its genotoxicity, the toxicity of the sulfonamides is the largest, the macrolide is the second, and the toxicity of quinolones is the weakest.
【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X171.5;X592

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