兔血清中褪黑激素的HPLC测定及其药动学研究

HPLC determination of melatonin and study on its pharmacokinetics in rabbits

目的 建立褪黑激素 (MLT)在兔血清中的高效液相色谱测定方法 ,研究MLT在兔体内的药动学。方法 采用YWG -C18色谱柱 4 .6mm× 1 50mm ;以乙腈 磷酸缓冲液 ( 41∶59)为流动相 ,维拉帕米作内标 ,流速为 1mL·min- 1,荧光检测 ,激发波长 2 80nm ,发射波长 3 40nm。结果 MLT在 0 .5～ 64 μg·L- 1范围内具有良好的线性关系 ,最低检测浓度为 0 .2 5μg·L- 1,平均萃取回收率为 ( 82 .55± 5.3 3 ) % ,平均方法回收率为 ( 1 0 0 .1 2± 0 .98) % ,日内RSD <5% ,日间RSD <5% ,家兔耳缘静脉注射MLT 0 .2 5mg·kg- 1,t1/ 2 β为 ( 1 .55± 0 .2 1 )h ,AUC0～ 8为 ( 2 7.73± 1 .0 3 ) μg·h·L- 1。结论 本法具有快速、简便、灵敏准确的特点 ,用于MLT生物样本分析 ,结果良好。

OBJECTIVE: A HPLC method was described for the analysis of melatonin (MLT) in serum and to study the pharmacokinetic of MLT in rabbits. METHODS: The YWG-C18 column (150 × 4.6 mm, 5 μm) was used. The mobile phase was consisted of a mixture of acetonitrile-phosphate (pH3.0). The flow rate was 1 mL&middotrain-1. Fluorescence detector was used with Ex at 280 nm and Em at 340 nm. Verapamil was used as the internal standard. RESULTS: A good linearity was obtained from 0.5∼64 μg &middot, L-1 of MLT in rabbit serum with r =0.9990. The lowest detectable concentration was 0.25 μg&middotL-1. While the average recovery of the method was (100.12 ±0.98)%, the RSD of intra-day and inter-day variation was less than 5%. The main pharmacokinetic parameters after iv administration of MLT in rabbits were t1/2β(1.55 ±0.21) h and AUCo∼∞ (27.73 ±1.03) μg&middoth&middotL-1, respectively. CONCLUSION: The established HPLC method was simple and accurate for the determination of MLT in serum.