高效液相色谱法测定鳗鲡各组织中的乙酰甲喹残留量

建立鳗鲡各组织中乙酰甲喹残留量的高效液相色谱测定方法,高效液相色谱检测条件为:采用SunFireTM C_(18)柱(4.6mm×150mm,3.5μm),柱温35℃;以甲醇∶水(40∶60,体积比)为流动相,流速为0.8mL·min~(-1);采用二极管阵列检测器,检测波长239nm。结果表明:在0.05~2.5μg·mL~(-1)范围内,乙酰甲喹具有良好的线性关系,含量与峰面积的相关系数达0.999以上;乙酰甲喹在鳗鲡肌肉、肾、肝和血浆中的检出限分别为3μg·kg~(-1)、15μg·kg~(-1)、15μg·kg~(-1)、15μg·L~(-1),鳗鲡各组织中乙酰甲喹回收率在76%~90%,相对标准偏差均小于10%(n=6)。本方法简便、快捷、灵敏度高,具有良好的重复性,满足鳗鲡各组织基质内乙酰甲喹残留量的快速定量分析的要求。     

乙酰甲喹分子印迹聚合物的制备及其应用

采用分子印迹技术,以α-甲基丙烯酸为功能单体,二甲基丙烯酸乙二醇酯为交联剂,合成出以乙酰甲喹为模板的分子印迹聚合物,利用合成的聚合物为填料制备固相萃取小柱,同时用不同的淋洗液与洗脱液对小柱吸附性进行评价.结果表明,利用10%的乙腈为淋洗液,100%的乙腈为洗脱液,可以解决"样品泄露"问题,为后续工作提供一定的研究基础.     

乙酰甲喹在美洲鳗鲡体内的药物代谢动力学及残留研究

在水温(25±1)℃条件下,分别采用口灌和浸浴的给药方式,以120mg·kg~(-1)的单剂量混饲口灌及5mg·L~(-1)浸浴18h给予乙酰甲喹后,用高效液相色谱法测定血浆、肌肉、肝脏及肾脏中的药物浓度,研究不同给药方式下乙酰甲喹在美洲鳗鲡体内的药代动力学特征及残留情况。结果表明:乙酰甲喹原药在美洲鳗鲡体内吸收良好、代谢快、体内残留少。口灌给药后,血浆中药物浓度达峰时间T_(max)为0.75h,达峰质量浓度C_(max)为4 115μg·L~(-1),消除相半衰期T_(1/2)为7.40h,总体消除率CL/F为41.89L·kg~(-1)·h~(-1),72h后血浆、肌肉、肝脏及肾脏中几乎检测不到原药;浸浴给药血浆中药物浓度于0.25h达峰,达峰质量浓度C_(max)为435.6μg·L~(-1),消除相半衰期T_(1/2)为0.26h,总体消除率CL/F为1.241L·kg~(-1)·h~(-1),2.5h后各组织中几乎检测不到原药。2种方式给药乙酰甲喹在美洲鳗鲡血浆中分布均符合药动学一室开放模型。     

Metabolism of Mequindox in Isolated Rat Liver Cells

Mequindox （MEQ）, 3-methyl-2-quinoxalinacetyl-l,4-dioxide, is widely used in Chinese veterinary medicine as an antimicrobial agent and feed additive. Its toxicity has been reported to be closely related to its metabolism. To understand the pathways underlying MEQ＇s metabolism more clearly, we studied its metabolism in isolated rat liver cells by using liquid chromatography coupled with electrospray ionization hybrid linear trap quadrupole orbitrap （LC-LTQ-Orbitrap） mass spectrometry. The structures of MEQ metabolites and their product ions were readily and reliably characterized on the basis of accurate MS2 spectra and known structure of MEQ. Eleven metabolites were detected in isolated rat liver cells, two of which were detected for the first time in vitro. The major metabolic pathways reported previously for in vitro metabolism of MEQ in rat microsomes were confirmed in this study, including N O group reduction, carbonyl reduction, and methyl monohydroxylation. In addition, we fotmd that acetyl hydroxylation was an important pathway of MEQ metabolism. The results also demonstrate that cellular systems more closely simulate in vivo conditions than do other in vitro systems such as microsomes. Taken together, these data contribute to our understanding of the in vivo metabolism of MEQ.     

乙酰甲喹对小新月菱形藻、等鞭金藻3011的毒性效应

通过考察乙酰甲喹对小新月菱形藻(Nitzschia closterium f.minutissima)、等鞭金藻(Isochrysis galbana Parke3011)的生长抑制和对叶绿素a、总超氧岐化酶(T-SOD)活性以及丙二醛(MDA)浓度的影响,研究了乙酰甲喹对2种微藻的毒性效应,为评价兽药乙酰甲喹的使用安全性和保护养殖环境提供基础数据。结果表明,乙酰甲喹对2种微藻的生长抑制作用随质量浓度的增加而增大,乙酰甲喹对小新月菱形藻的24 h-EC50(半数有效浓度)为4.73 mg·L~(-1)、对等鞭金藻3011的24 h-EC50为2.14 mg·L~(-1),乙酰甲喹对2种微藻均属于高毒物质,等鞭金藻3011更敏感。暴露24 h后,随着乙酰甲喹质量浓度的升高,小新月菱形藻叶绿素a浓度下降而等鞭金藻3011叶绿素a浓度基本不受影响;2种微藻的T-SOD活性随着乙酰甲喹质量浓度的升高均显著增加,各实验组MDA浓度也高于对照组,等鞭金藻3011更敏感,说明乙酰甲喹对2种微藻均能造成氧化胁迫,对细胞造成氧化损伤。     

喹噁啉类药物对醛固酮合成和分泌影响的研究进展

喹噁啉类药物的肾上腺毒性作用主要表现为对醛固酮合成和分泌的影响。随着喹噁啉类药物作为抗菌促生长剂在畜牧业中的广泛应用,其肾上腺毒性逐渐受到关注。本文从醛固酮合成过程和肾素-血管紧张素-醛固酮系统这两方面,综述了近年来该类药物对醛固酮影响的研究进展,旨在为后期进一步揭示喹噁啉类药物的肾上腺毒性做出贡献。