Studies On Hepatic Absorption Pharmacokinetics Of Glutathione

Aim A rapid quantification method of glutataione determination by liquid chromatography tandem mass spectrometry(LC-MS/MS)was developed in rat liver in order to investigate the absorption kinetics of glutataione in rat,and then comparing and analyzing the results with endogenous glutataione in rat liver.Method Samples were collected and derived by derivatization reagent,then determinated following the step of precipitation and dilution to appropriated multiples by ice methanol.In this experiment,captopril served as an internal standard(I.S.)which can derive with glutathione at the same time.The separation was performed on the Extend-C18 column.10 mM ammonium acetate-water-methanol was used as mobile phase,the flow rate and temperature of HPLC system maintained at 1.0 mL/min and 40 ? respectively.20 ?L samples were injected.Mass spectrometry which equipped with ESI source was selected Multiple reaction monitoring(MRM)detection mode was carried out with the precursor to production transitions for glutataione derivate of m/z 505.5? 358.6,captopril derivate of m/z 415.7 ? 216.2.The stability,specificity,matrix effects,the low limit of quantification,linearity,precision,accuracy and recovery were evaluated completely for the validations of method for liver tissues.Results Rats were administrated at medium doses which contained with 800 mg/kg glutataione and 4 mL/kg normal saline by oral gavage.The control groups were administrated at the same volume of normal saline by oral gavage.The following results came from three different methods to deduct of endogenous glutataione:(1)Deducting the average blank background which belongs to the same gender with the experimental group,the pharmacokinetic parameters of male and female rats as below:Cmax:0.99 ± 0.47 mg/g and 0.62 ± 0.31 mg/g,respectively;AUC(0-t):4.16 ± 1.15 mg/g·h and 1.69 ± 1.23 mg/g·h,respectively.(2)Deducting the blank background one-to-one according to the dosing time:Cmax was 0.87 ± 0.43 mg/g and AUC(0-t)was 2.92 ± 1.88 mg/g·h.(3)Deducting average blank background without gender or dosing time differentiate:Cmax was 0.83 ± 0.39 mg/g and AUC(0-t)was 2.94 ± 1.94 mg/g-h.The drug concentration-time curves got from three different analysis methods above all presented a trend which obeyed drug oral administration rule.It shows that glutataion has a certain targeting function for livers.