Lang W
Department of Radiobiochemistry, Dr. Madaus GmbH & Co., Cologne, FRG.
Pharmacology. 1988;36 Suppl 1:158-71. doi: 10.1159/000138436.
After oral or intravenous administration of 14C-rhein to male rats, blood concentrations were measured for up to 48 h. Both mean blood level curves and also the calculated pharmacokinetic constants show a fairly good conformity. Organ distribution was measured up to 2 days after intravenous and up to 7 days after oral application. In most organs the activity is lower than in plasma with very low values in testicles and in brain. Higher values are found in the main excretion organ, the kidney. The plasma protein binding of 14C-rhein is very high both in rat and human serum. Absorption in or adsorption on erythrocytes is very small. Rhein and its metabolites are excreted by kidney and liver. Biliary-excreted rhein metabolites are easily reabsorbed and finally excreted with urine. In bile, there are mainly two conjugated metabolites of rhein, whereas in urine also larger amounts of rhein and one or two additional metabolites can be detected. All metabolites seem to be conjugates, because they can be split by glucuronidase/arylsulfatase to rhein. Rhein is absorbed after oral application by about 50-60% and after administration into the colon by about 50%.
给雄性大鼠口服或静脉注射14C-大黄酸后，测量长达48小时的血药浓度。平均血药浓度曲线和计算所得的药代动力学常数均显示出相当良好的一致性。在静脉注射后2天内以及口服后7天内测量器官分布情况。在大多数器官中，放射性活性低于血浆，在睾丸和脑中的值非常低。在主要排泄器官肾脏中发现的值较高。14C-大黄酸在大鼠和人血清中的血浆蛋白结合率都非常高。在红细胞中的吸收或吸附非常少。大黄酸及其代谢产物通过肾脏和肝脏排泄。经胆汁排泄的大黄酸代谢产物很容易被重吸收，最终随尿液排出。在胆汁中，主要有两种大黄酸的结合代谢产物，而在尿液中也能检测到大量的大黄酸以及一两种其他代谢产物。所有代谢产物似乎都是结合物，因为它们可被葡萄糖醛酸酶/芳基硫酸酯酶裂解为大黄酸。大黄酸口服后的吸收率约为50-60%，经结肠给药后的吸收率约为50%。
