P糖蛋白抑制剂维拉帕米对米诺环素在小鼠体内药动学与脑组织分布的影响

Impact of P-glycoprotein inhibitor verapamil on the pharmacokinetics and brain tissue distribution of minocycline in mice

目的分析P糖蛋白抑制剂维拉帕米对米诺环素在小鼠血浆与脑组织的药物代谢动力学影响,探讨P糖蛋白参与的米诺环素耐药与药物外排机制。方法将192只小鼠随机分为对照组与维拉帕米组,每组各96只,按照米诺环素、维拉帕米临床剂量折算为小鼠实际给药量,维拉帕米组小鼠在取材前3 d灌胃给予维拉帕米1 mg/kg,第4天两组小鼠灌胃给药35 mg/kg米诺环素。给药后每组小鼠按照药物代谢动力学预设时间点获取血浆、脑组织样本。运用高效液相色-三重四极杆质谱法测定米诺环素血浆、脑组织药物浓度,绘制药物浓度-时间曲线,同时采用非房室模型获得药代动力学参数并计算米诺环素脑分布系数,最后对两组数据进行比较分析。结果药代动力学分析结果显示,相较对照组,维拉帕米组小鼠在脑组织中米诺环素药峰浓度(C_(max))(1266.3±248.7)ng/mL显著增大(P<0.001),平均驻留时间(MRT)(16.3±1.5)h显著延长(P<0.05),药物浓度-时间曲线下面积(AUC)(15053.8±1839.3)(h·ng/mL)显著增大(P<0.0001),表观清除率(CL)显著降低(P<0.05)。血浆中,相比对照组维拉帕米小鼠AUC(18872.7±1462.3)(h·ng/mL)、C_(max)(2593.6±362.2)ng/mL显著增加(P<0.001),MRT(9.0±0.8)h也显著延长(P<0.05)。此外,维拉帕米组的脑部米诺环素分布系数(84.6±7.9)%显著升高(P<0.05)。结论P糖蛋白抑制剂维拉帕米预给药能够增加小鼠米诺环素血、脑药物的暴露程度,延长驻留时间,降低清除率,提高米诺环素的生物利用度,提示米诺环素可能为P糖蛋白的潜在底物。

Objective To investigate the impact of the P-glycoprotein inhibitor verapamil on the pharmacokinetics of minocycline in mouse plasma and brain tissue,with a focus on exploring the involvement of P-glycoprotein in minocycline resistance and drug efflux mechanisms.Methods A total of 192 mice were randomly divided into two groups:the control group and the verapamil group,with 96 mice in each group.Clinical doses of minocycline and verapamil were converted to appropriate dosages for mice.The verapamil group of mice received an oral administration of 1 mg/kg verapamil for three days before sample collection.On the fourth day,both groups of mice received oral administration of 35 mg/kg minocycline.The control group received oral minocycline without verapamil pretreatment.Blood plasma and brain tissue samples were collected at predetermined pharmacokinetic time points.High-performance liquid chromatography coupled with triple quadrupole mass spectrometry was employed to determine minocycline concentrations in blood plasma and brain tissue.Pharmacokinetic parameters were obtained using a non-compartmental model,and the minocycline brain distribution coefficient was calculated.Finally,a comparative analysis of the data from both groups was performed.Results In brain tissue,Pharmacokinetic analysis revealed significant increases in minocycline peak concentration(C_(max))(1266.3±248.7)ng/mL,mean residence time(MRT)(16.3±1.5)h,and area under the curve(AUC)(15053.8±1839.3)(h·ng/mL)in verapamil-treated mice compared to the control group(P<0.05).The apparent clearance rate(CL)was significantly reduced in the verapamil group(P<0.05).In plasma,verapamil-treated mice showed significant increases in AUC(18872.7±1462.3)(h·ng/mL),C_(max)(2593.6±362.2)ng/mL(P<0.001),and prolonged MRT(9.0±0.8)h(P<0.05).Furthermore,the verapamil group exhibited a significantly elevated minocycline brain distribution coefficient(84.6±7.9)%(P<0.05).Conclusion Pre-treatment with the P-glycoprotein inhibitor verapamil can increase minocycline exposure in mouse plasma and brain tissue,prolong residence time,decrease clearance and enhance minocycline's bioavailability,indicating that minocycline may be a potential substrate of P-glycoprotein.