α-与β-甘草酸在小鼠体内分布的研究

目的 探讨甘草酸(glycyrrhizic acid, GL) 的两个差向异构体α-GL 和β-GL 在小鼠体内的分布及其特征。 方法 运用HPLC-UV 法检测小鼠单次iv α-GL 或β-GL 53 mg·kg^-1后5、15、30、60 和180 min 时体内各组织脏器中的药物含量, 比较、评价两者的分布差异及特征。 结果 α-GL 和β-GL iv 后分布迅速,除血外, 肝中含量最高, 肺、肾、脂肪、心、卵巢、肠、脾、睾丸、肌肉中药物含量依次减小, 脑中最低;肠肝循环的第二峰现象出现在30 min 时;α-GL iv 后早期肝含量显著高于β-GL, 血及其余组织脏器药物含量明显低于β-GL 或与其相近;随时间的延长药物含量迅速降低的同时肠浓度渐高, 至180 min 时α-GL 各组织脏器(除肠外) 药物浓度接近或低于检测限, β-GL 则仍维持较高浓度, 是峰值的30 %~ 70 %。 结论 小鼠iv α-GL 后在体内呈肝分布特异性, 转化成GA 的速率高于β-GL, 无组织蓄积;而β-GL 在体内分布广泛, 代谢较慢, 有蓄积的可能。

Studies on distribution in mice tissues of α-Glycyrrhizic acid and β-Glycyrrhizic acid

AIM: To examine the characters of distribution of two epimers of glycyrrhizic acid (GL) including α-GL and β-GL in mice. METHODS: After iv administration of a single 53.0 mg·kg^-1 α-GL or β-GL in mice at 5, 15, 30, 60, and 180min, the concentrations of α-GL or β-GL in some tissues were determined by HPLCUV method, and the features of distribution of α-GL and β-GL were evaluated and compared. RESULTS: α-GL and β-GL were all quickly distributed.Except the plasma, the concentrations of α-GL and β-GL were higher in the liver than that in other tissues.The second peak of enterohepatic circulation could be observed at 30 min after iv administration.The concentration of α-GL in the liver was significantly higher than that of β-GL, but it was lower than or similar to that of β-GL in the plasma and other tissues after iv.Then the levels declined rapidly in all tissues but the intestine at 180min after iv administration, meanwhile, β-GL maintained rather high concentrations in various tissues, which were all 30 %-70 % of the peaks. CONCLUSION: After iv administration, α-GL is target to the liver, and can be efficiently converted to more α-GA than β-GL, and it nearly has no accumulation in the tissues.The tissue distribution of β-GL inmice appears to be wild throughout the body, and the metabolism is slower than that of α-GL to accumulate in some tissues.