硒对六价铬引起鸡脑氧化应激损伤的影响研究

发布时间：2018-06-19 19:02

本文选题：六价铬 + 亚硒酸钠　；参考：《山东农业大学》2017年硕士论文

【摘要】：大量摄入六价铬能促使机体产生癌细胞,并引发肝毒性、脂质代谢紊乱、肠系膜淋巴结病变等影响。早在2007至2011年期间,美国疾控中心就将铬元素列为优先检测物质,但由于人类不规范的生产活动,个体仍可通过食品、饮水、日用品等多种途径摄入六价铬。有研究表明,硒能通过复杂的相互作用与重金属结合来减缓金属毒性,但硒与六价铬的相互影响目前研究还很少,本实验目的在于探索硒对六价铬在鸡脑组织中的影响,并从而确定缓解鸡脑毒性作用的最适添加剂量。本试验首先对海兰褐公鸡进行了急性攻毒实验,通过测定半数致死量(LD_(50))确定攻毒剂量为6%LD_(50)。随后将105只1日龄的海兰褐鸡随机分为七组进行试验,分别为对照组、六价铬中毒组(6%LD_(50)K_2Cr_2O_7)和硒添加组(0.31、0.63、1.25、2.50、5.00mg/kg Na_2SeO_3+6%LD_(50)K_2Cr_2O_7)。每组15只鸡,分别在14天、28天和42天采样,对实验鸡进行称重、并按标准方法处死,取其脑组织称重,一部分用于制备病理切片,另一部分用于各种指标的检测分析。通过测定脑体比、SOD、MDA、GSH、Ca~(2+)-ATPase和MMP水平来阐述硒与六价铬对鸡脑的影响。结果显示,5.00 mg/kg硒添加组的脑体比和SOD水平显著高于同期其它试验组及攻毒组,并随时间延长而使脑体比下降。中毒组的GSH水平明显低于对照组,硒的添加有效恢复GSH水平,并在1.25 mg/kg硒添加组中达到最高,但随硒含量增加脑内GSH水平又明显下降。MDA水平在中毒组中最高,在0.63 mg/kg硒添加组中达到最低,而在5.00 mg/kg硒添加组中的GSH和MDA水平与中毒组相比均无明显差异。Ca~(2+)-ATPase酶主要存在于线粒体内腔、肌质网和内质网囊腔,在本次试验中攻毒组、解毒试验组Ca~(2+)-ATPase水平都显著低于对照组,硒的添加在一定程度上恢复Ca~(2+)-ATPase水平,其中0.63 mg/kg硒添加组效果最佳,但硒剂量过高时则会导致Ca~(2+)-ATPase水平降低,2.50和5.00 mg/kg硒添加组中的Ca~(2+)-ATPase水平显著低于中毒组。线粒体活性测定结果与Ca~(2+)-ATPase酶测定结果相吻合,中毒组MMP水平明显低于对照组,硒含量增多能明显恢复MMP水平,并在0.63 mg/kg硒添加组中效果最好,但随硒含量增加而下降,5.00 mg/kg硒添加组MMP水平可达到中毒组MMP水平。病理组织学检测结果显示,0.63 mg/kg硒添加组对大小脑的空泡化神经元和毛细血管、小血管水肿有明显恢复作用,浦肯野细胞核裂解减少,在一定程度上保护了浦肯野细胞层,避免由六价铬引起的浦肯野细胞数量减少和空泡化。上述结果表明,硒的添加有利于缓解由六价铬引起的鸡脑组织的氧化应激,但硒的过量添加则会增加六价铬对脑组织的毒性,起到协同毒性作用。
[Abstract]:A large amount of chromium hexavalent can promote the production of cancer cells and lead to hepatotoxicity, lipid metabolism disorder, mesenteric lymph node lesions and other effects. As early as from 2007 to 2011, the CDC of the United States listed chromium as a priority substance, but due to human non-standard production activities, individuals can still take in hexavalent chromium through food, drinking water, daily necessities and other channels. Some studies have shown that selenium can attenuate metal toxicity through complex interactions with heavy metals, but the interaction between selenium and hexavalent chromium is rarely studied. The purpose of this study is to explore the effect of selenium on hexavalent chromium in chicken brain. The optimum dosage of additives for alleviating the brain toxicity of chicken was determined. In this experiment, an acute drug attack test was carried out on the Hailan Brown Rooster, and the dose was determined to be 6LDD / L ~ (50) by determining the lethal dose (LD50) of Hailan Brown Rooster (Hailan Brown Rooster). After that, 105 1-day-old Hailan brown chickens were randomly divided into seven groups: control group (control group) and selenium supplementation group (0.31 ~ (0.631) 0.252.50mg / kg Na2SeO3 / kg Na2SeO36 LD50 / kg Na2SeO3 / kg group. 15 chickens in each group were sampled at 14 days for 28 days and 42 days respectively. The chickens were weighed and killed according to the standard method. One part of the brain tissue was taken for the preparation of pathological sections and the other part was used for the detection and analysis of various indexes. The effects of selenium and hexavalent chromium on the chicken brain were studied by measuring the levels of SODX / MDAA GSH / Cam ~ (2 +) -ATPase and MMP. The results showed that the ratio of brain to body and the level of sod in the 5. 00 mg/kg selenium added group were significantly higher than those in other experimental groups and drug attack groups in the same period, and the ratio of brain to body was decreased with the prolongation of time. The level of GSH in the poisoning group was significantly lower than that in the control group, and the level of GSH was recovered effectively by adding selenium, and reached the highest level in the group supplemented with 1. 25 mg/kg selenium. However, with the increase of selenium content, the level of GSH in the brain decreased significantly. The level of GSH in the brain was the highest in the poisoning group. The level of GSH and malondialdehyde (mg/kg) was the lowest in the 0.63 mg/kg se supplemented group, but there was no significant difference in GSH and MDA levels between the 5. 00 mg/kg se added group and the poisoning group. The enzyme mainly existed in the mitochondria, sarcoplasmic reticulum and endoplasmic reticulum sac. In this experiment, the level of GSH and MDA in the poisoning group was not significantly different from that in the poisoning group. In the detoxification test group, the level of Caanzao 2 + -ATPase was significantly lower than that of the control group, and the selenium supplementation had the best effect in some extent, especially in the 0. 63 mg/kg se added group. However, when the dosage of selenium was too high, the level of Caanzao 2 + -ATPase was significantly lower in the 2. 50 and 5. 00 mg/kg se added groups than in the poisoned group. The results of mitochondrial activity were in agreement with the results of Cajian2 + -ATPase enzyme assay. The level of MMP in the poisoned group was significantly lower than that in the control group, and the increase of selenium content could significantly restore the level of MMP, and the effect was the best in the 0. 63 mg/kg se added group. However, with the increase of selenium content, the level of MMP in 5.00 mg/kg selenium supplementation group could reach the level of toxic group. The histopathological results showed that the 0. 63 mg/kg selenium supplementation group could significantly recover the vacuolated neurons and capillaries and the edema of small blood vessels in the brain, and the cleavage of Purkinje nucleus decreased, and the cell layer of Purkinje was protected to a certain extent. Avoid reduced number and vacuolation of Purkinje cells caused by hexavalent chromium. The results showed that the addition of selenium was beneficial to alleviate the oxidative stress in chicken brain tissue induced by hexavalent chromium, but the excessive addition of selenium could increase the toxicity of hexavalent chromium to brain tissue and play a synergistic effect.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S858.31

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