Department of Pharmacology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 229-8501, Japan.
Res Vet Sci. 2009 Dec;87(3):455-7. doi: 10.1016/j.rvsc.2009.03.018. Epub 2009 Apr 29.
We investigated how long in vivo hepatic cytochrome P450 (CYP) activity is enhanced even after discontinuation of repeated oral administration of phenobarbital (PB) in dogs using antipyrine clearance, which reflects hepatic CYP activity. A single antipyrine (5 mg/kg) was administered intravenously before and 34 days after the repeated oral administration of PB (5 mg/kg, bid) and 2, 4, 6, and 8 weeks after the discontinuation of PB in 5 dogs. Antipyrine clearance was increased by the repeated administration of PB, and remained increased 2 and 4, but not 6 and 8 weeks after the discontinuation of PB. The result suggests that hepatic CYP activity was enhanced by the repeated administration of PB, and this enhancement may last for at least 4 weeks even after its discontinuation.
我们使用反映肝 CYP 活性的安替比林清除率来研究在狗中，即使停止重复口服苯巴比妥（PB）后，体内肝 CYP 活性增强能持续多长时间。在 5 只狗中，在重复口服 PB（5mg/kg，bid）之前和之后第 34 天以及在停止 PB 后 2、4、6 和 8 周时，单次静脉注射安替比林（5mg/kg）。重复给予 PB 可增加安替比林清除率，并且在停止 PB 后 2 和 4 周仍保持增加，但在 6 和 8 周时则没有增加。结果表明，肝 CYP 活性通过重复给予 PB 而增强，即使在停止 PB 后，这种增强至少可以持续 4 周。
