Activities of biotransformation enzymes in pheasant (Phasianus colchicus) and their modulation by in vivo administration of mebendazole and flubendazole

Basal activities of certain pheasant hepatic and intestinal biotransformation enzymes and modulation of their activities by anthelmintics flubendazole (FLBZ) and mebendazole (MBZ) were investigated in subcellular fractions that were prepared from liver and small intestine of control and FLBZ or MBZ treated birds. Several oxidation, reduction and conjugation enzyme activities were assessed. In the liver, treatment of pheasants by FLBZ or MBZ caused very slight or no changes in monooxygenase activities and conjugation enzymes. More significative changes were detected in small intestine. Metyrapone and daunorubicin reductase activities were increased by both substances in the liver. This is the first evidence that certain benzimidazoles modulate reductases of carbonyl group. With respect to the relatively slight extent of the changes caused by FLBZ or MBZ we can assume that repeated administration of therapeutic doses of both FLBZ and MBZ has probably no serious influence on pheasant biotransformation enzyme system.     

Use of flubendazole as a therapeutic agent against rotifers (Brachionus plicatilis) in intensive cultures of the harpacticoid copepod Tisbe holothuriae

Copepods are well known to be the optimal live feed for most species of marine fish larvae. Still copepods are rarely used in marine hatcheries worldwide. Lack of efficient production techniques are among the reasons for this. Consequently, Artemia and rotifers are utilized in commercial settings. One problem in intensive production of copepods is contamination with rotifers. Rotifers have higher growth rates than copepods and consequently will compete out the copepods when accidentally introduced to the copepod production systems. Once contamination has occurred, the only cure has been to shut down production and subsequently use a therapeutic agent to eliminate all zooplankton in the system before restart with a stock culture free of rotifers. We tested flubendazole as a mean of controlling rotifers (Brachionus plicatilis) in intensive laboratory cultures of the harpacticoid copepod (Tisbe holothuria). Flubendazole was lethal to rotifers in concentrations as low as 0.05 mg L^?1. There was no significant effect on the concentration of copepods, even at the highest concentration tested, i.e. 5.0 mg L^?1 flubendazole. We conclude that flubendazole is an effective drug for control of B. plicatilis in T. holothuriae batch cultures.     

The effects of flubendazole and mebendazole on cytochromes P4501A in pheasant hepatocytes

Many benzimidazoles are known inducers of cytochromes P4501A (CYP1A) in laboratory animals and cell lines. As flubendazole and mebendazole are benzimidazole anthelmintics often used in a pheasant, in the present study an effect of these drugs in primary cultures of pheasant (Phasianus colchicus) hepatocytes was investigated. After 48 h incubation of the hepatocytes with the benzimidazoles (0.2-5 microM), CYP1A activities -- ethoxyresorufin O-deethylation (EROD) and methoxyresorufin O-demethylation (MROD) activities were measured and the CYP1A protein levels were determined by Western blotting. None of the tested benzimidazoles influenced the CYP1A protein content. No pharmacologically significant enhancement of CYP1A after exposure of the hepatocytes to flubendazole and mebendazole was found. Inhibition of the EROD/MROD activities caused by both tested substances was observed only at the highest concentration (5 microM). From a point of view of CYP1A induction or inhibition, the treatment of pheasants by both anthelmintics tested seems to be safe. Our study demonstrates the inter-species differences in CYP1A inducibility and the importance of induction/inhibition studies on target animals.     

高效液相色谱法检测羊鸡组织中氟苯达唑、噻苯达唑及其代谢物残留量的研究

建立了一种可同时检测羊组织（肌肉、肝脏、肾脏、脂肪）、鸡组织（肌肉、肝脏）中氟苯达唑及代谢物2-氨基氟苯达唑、噻苯达唑及代谢物5-羟基噻苯达唑药物残留的高效液相色谱检测方法。结果表明：氟苯达唑及代谢物2-氨基氟苯达唑、噻苯达唑及代谢物5-羟基噻苯达唑在0.02～1.5μg/mL浓度范围内呈良好的线性关系r,均大于0.999。方法的定量限为20μg/kg。在鸡组织（肌肉、肝脏）中,两种药物及其代谢物在20～800μg/kg的添加浓度范围内,其回收率范围在60%～100%之间;在羊组织（肌肉、肝脏、肾脏、脂肪）中,两种药物及其代谢物在20～200μg/kg的添加浓度范围内,其回收率范围在60%～100%之间;批内变异系数均小于15%、批间变异系数均小于20%。     

高效液相色谱法测定动物组织中氟苯达唑、噻苯达唑及代谢物残留量的研究

建立了一种可同时检测猪、牛组织(肌肉、肝脏、肾脏、脂肪、牛奶)中氟苯达唑及代谢物2-氨基氟苯达唑、噻苯达唑及代谢物5-羟基噻苯达唑药物残留的高效液相色谱-紫外检测法。猪、牛组织样品经乙腈提取,加入Na_2SO_4盐析去杂质,异辛烷去脂肪,MCX柱净化。以0.02 mol/L乙酸铵溶液和乙腈溶液为流动相,梯度洗脱,检测波长306 nm。结果表明,氟苯达唑及代谢物2-氨基氟苯达唑、噻苯达唑及代谢物5-羟基噻苯达唑在0.01~2.0μg/mL浓度范围内呈良好的线性关系,r均大于0.99。猪、牛组织中方法的最低定量限分别为5、20μg/kg。猪、牛组织中氟苯达唑及代谢物2-氨基氟苯达唑、噻苯达唑及代谢物5-羟基噻苯达唑分别在5~200、20~200μg/kg的浓度添加水平上,其回收率范围在60%~100%之间,批内相对标准偏差小于15%、批间相对标准偏差小于20%。