【摘要】：喹烯酮(Quinocetone，簡稱QCT)是由中國農(nóng)業(yè)科學院蘭州畜牧與獸藥研究所研究合成的一類喹惡啉類藥物，具有喹惡啉-l,4-二氧化物（quinoxaline-1,4-dioxides,QdNOs）的基本結(jié)構(gòu)，可抑制腸道內(nèi)多種細菌的生長和繁殖，包括金葡菌、沙門氏菌及大腸桿菌等，主要用于牛、豬及家禽以發(fā)揮其促生長、改善腸道菌群、促進蛋白質(zhì)吸收及合成作用。近年來，有研究發(fā)現(xiàn)喹惡啉類衍生物卡巴氧和喹乙醇，具有潛在的誘突變性和致癌性。由于喹烯酮與該兩種藥物具有相同的基本結(jié)構(gòu)，喹烯酮藥物的使用安全性也逐漸受到人們的關(guān)注。相關(guān)資料顯示，QCT可能導致哺乳動物細胞株的強致突變作用，對HepG2細胞株引起DNA損傷。但目前有關(guān)QCT引起的免疫毒性研究有限，因此選用Sparague-Dawley大鼠（簡稱SD大鼠）進行喹烯酮亞慢性暴露，以評價喹烯酮對于哺乳動物的免疫毒性作用，并通過氧化應激狀態(tài)對其相關(guān)機制進行探討。 目的：探討亞急性QCT暴露對SD大鼠的免疫毒性作用，并初步探討QCT致免疫毒性與氧化應激的相互關(guān)系。 方法：健康雄性SD大鼠32只，隨機分為以下四組：正常對照組(control):0mg/kg/day；喹烯酮低劑量組(QCT-H):50mg/kg/day；喹烯酮中劑量組(QCT-M):800mg/kg/day；喹烯酮高劑量組(QCT-H):2400mg/kg/day。每日記錄體重及進食量，喂養(yǎng)至28天采用頸椎脫臼處死，記錄脾臟、胸腺等主要臟器重量，留置一半脾臟作組織病理檢查，剩余部分制備單細胞懸液，以絲裂原刺激法測量T、B淋巴細胞增殖能力、以YAC-1細胞作靶細胞測定NK細胞殺傷活性。彗星實驗評價脾分離細胞的DNA損傷程度。制作脾組織冰凍切片，進行DHE染色，觀察熒光強度，并計算其平均熒光密度。制備脾線粒體勻漿，檢測GSH水平及GPx，SOD和CAT活力。 結(jié)果：（1）高劑量QCT組SD大鼠脾臟組織表現(xiàn)出脾竇淤血改變；T、B淋巴細胞，NK細胞活性顯著降低，差異有顯著性(P 0.01)。 （2）彗星實驗結(jié)果顯示喹烯酮暴露組OTM值與Tail DNA值較對照組均可見劑量依賴性增加，中、高劑量組與對照組檢測結(jié)果存在顯著性差異(P 0.01)。 （3）脾細胞ROS水平呈劑量依賴性升高，喹烯酮高劑量組GSH、CAT、GPx與對照組相比均出現(xiàn)顯著降低(P 0.01)。 結(jié)論：高劑量喹烯酮亞急性暴露能夠引起SD大鼠免疫靶器官組織損傷，且能導致脾組織DNA損傷，提示其對哺乳動物存在潛在的免疫毒性。喹烯酮亞急性暴露引起的免疫毒性跟其代謝中產(chǎn)生過量的ROS以及對抗氧化系統(tǒng)的抑制有直接關(guān)系。創(chuàng)新點：對喹烯酮亞急性暴露引起的SD大鼠免疫毒性進行評價，并從DNA損傷、氧化應激方面探討其產(chǎn)生免疫毒性作用的機制。
[Abstract]:Quinocetone (QCT) is a class of quinoxaline drugs studied and synthesized by Lanzhou Institute of Animal Husbandry and Veterinary Medicine, Chinese Academy of Agricultural Sciences. It has the basic structure of quinoxaline-14-dioxides (QdNOs) and inhibits the growth and reproduction of many bacteria in the intestine. Including Staphylococcus aureus, Salmonella and Escherichia coli, mainly used in cattle, pigs and poultry to promote growth, improve intestinal flora, promote protein absorption and synthesis. In recent years, it has been found that quinoxaline derivatives carbamoxy and quindoquindox have potential mutagenicity and carcinogenicity. Because quinolone and these two drugs have the same basic structure, the safety of quinolone has been paid more and more attention. The relevant data showed that QCT might lead to strong mutagenicity in mammalian cell lines and DNA damage to HepG2 cell lines. However, the current studies on immunotoxicity induced by QCT are limited. Therefore, Sparague-Dawley rats (SD rats) were selected for subchronic exposure to quinolones in order to evaluate the immunotoxicity of quinolones to mammals. The mechanism of oxidative stress was discussed. Aim: to investigate the immunotoxicity of subacute QCT exposure to SD rats and the relationship between QCT induced immunotoxicity and oxidative stress. Methods: 32 healthy male Sprague-Dawley rats were randomly divided into four groups: normal control group (control): 0 mg / kg / day); low dose quinolone group (QCT-H): 50 mg / kg / day; QCT-M: 800 mg / kg / r / day; QCT-H: 2400mg / kg / day. Body weight and food intake were recorded daily. After 28 days of feeding, cervical vertebrae dislocated and killed, spleen, thymus and other main organs weight were recorded, and half of the spleen was kept for histopathological examination, and the remaining part was used to prepare single cell suspension. Mitogen stimulation was used to measure the proliferation of T _ (B) B lymphocytes, and YAC-1 cells were used as target cells to determine the cytotoxicity of NK cells. Comet assay was used to evaluate the degree of DNA damage in splenic isolating cells. The frozen sections of spleen tissue were made and DHE staining was performed to observe the fluorescence intensity and calculate the average fluorescence density. Spleen mitochondria homogenate was prepared to detect the level of GSH and the activity of SOD and CAT. Results: (1) the splenic tissue of SD rats in high dose QCT group showed a marked decrease in NK cell activity in splenic sinus congestion. The difference was significant (P0.01). (2). The results of comet assay showed that the OTM value and Tail DNA value in the quinolone exposed group were increased in a dose-dependent manner as compared with those in the control group. There was a significant difference between the high dose group and the control group (P0. 01). (3). The level of ROS in splenocytes was increased in a dose-dependent manner, and the GSH-CATGPx in the high dose group of quinolone was significantly lower than that in the control group (P0. 01). Conclusion: high dose quinolone subacute exposure can damage the immune target organs of SD rats and lead to DNA damage in spleen tissue, suggesting that it has potential immune toxicity to mammals. The immunotoxicity induced by subacute exposure to quinolone is directly related to the production of excessive ROS in its metabolism and the inhibition of the antioxidant system. Innovation: the immunotoxicity of SD rats induced by subacute exposure to quinolone was evaluated, and the mechanism of its immune toxicity was discussed from the aspects of DNA damage and oxidative stress.
【學位授予單位】：華中科技大學
【學位級別】：碩士
【學位授予年份】：2012
【分類號】：R114

【參考文獻】

相關(guān)期刊論文 前3條

1 郝利華;肖希龍;周宗燦;;穿梭質(zhì)粒pSP189/哺乳動物Vero細胞檢測系統(tǒng)在喹乙醇誘變分子機制研究中的應用[J];癌變.畸變.突變;2006年01期

2 霍艷;李波;;ICH免疫毒性評價指導原則介紹[J];中國藥事;2006年10期

3 喬賜彬，，薛彬，龔詒芬;免疫毒理學概況[J];中華預防醫(yī)學雜志;1994年04期

本文編號：2144772