微囊藻毒素对肉鸡的生物安全评价毕业论文
2021-06-08 01:13:21
摘 要
近年来,中国多处江河湖泊发生水华现象,其中以蓝藻为主的藻类能产生多种藻毒素,对人畜及水产等具有严重的危害作用。随着养殖技术的发展,一些养殖场会选择经过处理的藻类作为畜禽的饲料,而藻类饲料中残存的藻毒素会对畜禽有一定的危害作用。当人们食用这类畜禽,经过毒素的富集作用,会对人们的安全构成一定的威胁。
本课题的目标是通过研究以腹腔注射不同浓度的微囊藻毒素-LR(MC-LR)作用不同时间模拟肉鸡食用残留不同浓度藻毒素饲料的过程,根据肉鸡的肝脏组织和肾脏组织石蜡切片的观察与分析,从肝脏肾脏组织损伤方面评估其生物安全性。
论文的研究结果表明,经腹腔注射不同浓度的MC-LR作用不同时间后,同一只肉鸡所取的肝脏和肾脏,肾脏的损伤明显大于肝脏。就肉鸡的肝脏而言,MC-LR的浓度对于其肝脏损伤作用明显,随着MC-LR浓度的增加,肝脏的中毒程度加强;在MC-LR浓度为5µg/Kg和20µg/Kg的实验组,肝脏的中毒程度随MC-LR的作用时间增长先增加后恢复正常;在MC-LR浓度为50µg/Kg的实验组,肝脏的中毒程度随MC-LR的作用时间增长而增强,在12h达到重度中毒水平后一直维持。此外,在MC-LR作用相同时间下,MC-LR的浓度越高对肉鸡的肝脏损伤作用越强。就肉鸡的肾脏而言,MC-LR的作用时间对于其肾脏的损伤作用明显,而MC-LR的浓度对其肾脏的损伤作用不明显;在短作用时间内,肉鸡的肾脏中毒程度随作用时间增长而加剧,在12h后基本保持在中、重度中毒水平。因此,建议肉鸡养殖场使用藻类饲料时,应注意藻类饲料中藻毒素的含量应小于20µg/Kg,间隔时间不能小于48h。
关键词: 微囊藻毒素-LR;肝肾损伤;组织切片;生物安全性
Abstract
In recent years, a amount of rivers and lakes in China occurred bloom phenomenon, in which cyanobacteria can produce a variety of algal toxins that have harmful effects on human beings, livestock and aquatic products. With the development of breeding technology, some farms will choose algae treated as animal feed, and algal toxins attaching on algae feed will have some harmful effects on the animal. When people eat them, due to the accumulation of toxins, that will be a threat t the people healthy.
This topic goal is, through the research on different concentrations of MC-LR effecting on different time by intraperitoneal injection simulate the feed process that broiler chicken eat animal feed attaching algal toxins, according to the observation and analysis of paraffin sections of the chicken liver and kidney tissue, to evaluate biological safety by liver and kidney tissue.
The research results show that, kidney damage of chicken exposed different concentrations of MC-LR for different time by intraperitoneal injection was significantly greater than those the liver. In terms of liver of broilers chicken, the concentration of MC-LR has significantly influence in liver damage, with MC-LR concentration increasing, the degree of liver damage strengthening; in 5µg/kg and 20µg/kg MC-LR experimental group, the degree of liver damage increases with the effect time growth at first and then returns to normal; in the experimental group 50µg/kg MC-LR, the degree of liver damage increases with the effect time growth, reaching the severe damage at 12h ,being maintained this level after that. In addition, at the same action time of MC-LR, the higher its concentration is, the more serious the broiler chicken liver damage is. In terms of broiler chicken kidney, the effect time of MC-LR has obvious influence in kidney damage, contrary to the concentration of MC-LR; in short time, chicken kidney damage degree exacerbates with the time of growth, remaining at severe damage level after 12h. Therefore, it is suggested that, when algal feed is used, chicken farms should pay attention to that the content of algal toxins in algae feed should be less than 20 µg/kg and effect time can not be less than 48h.
Key words: microcystin-LR; liver and kidney damage; tissue section; biological safety
目 录
第1章 绪论 3
1.1 微囊藻毒素的物理化学性质 3
1.2 微囊藻毒素的生物学效应 3
1.2.1 微囊藻毒素的肝毒性 3
1.2.2 微囊藻毒素的肾毒性 3
1.2.3 微囊藻毒素的其他毒性 2
1.3 微囊藻毒素对肝肾损伤的研究进展 2
1.4 本课题研究目的、主要内容及研究意义 2
1.4.1 研究目的 2
1.4.2 主要内容 3
1.4.3 研究意义 3
第2章 实验材料及方法 4
2.1 实验材料及仪器设备 4
2.1.1实验材料 4
2.1.2实验仪器 4
2.1.3 主要试剂 4
2.2 实验方法 5
2.2.1 腹腔注射微囊藻毒素 5
2.2.2 解剖提取肉鸡的肝脏和肾脏 5
2.2.3 制作肝脏和肾脏的石蜡切片并拍照记录 6
2.2.4 制定中毒等级划分依据 6
第3章 实验结果 7
3.1 养殖鸡的肝脏切片观察及描述 7
3.2 养殖鸡的肾脏切片观察及描述 11
3.3 肉鸡的肝脏和肾脏中毒等级结果的数字化处理 14
3.3.1 肉鸡的肝脏中毒等级结果的数字化处理 14
3.3.2 肉鸡的肾脏中毒等级结果的数字化处理 14
3.4 结果分析 16
第4章 结论与展望 17
参考文献 18
致谢 20
第1章 绪论
1.1 微囊藻毒素的物理化学性质
微囊藻毒素(MC)是一种单环七肽物质,由于多肽中两种可变氨基酸组成的不同,具有多种异构体。其中存在最普遍、含量最多的是MC-LR,MC-RR,MC-YR这3种微囊藻毒素(L、R、Y分别代表亮氨酸、精氨酸和酪氨酸)。它们被认为是潜在的1和2A型蛋白磷酸酶的抑制剂也是动物皮肤和肝脏的肿瘤抑制剂[1]。国内外研究最多的主要是MC-LR和MC-RR。Liu I等研究发现,MC-LR的急性毒性最强,MC-YR次之,MC-RR最弱[2]。
微囊藻毒素物理特性有以下几点: