载脂蛋白M在大鼠体内清除及分布

Clearance and distribution of ^(125)I-labeled apolipoprotein M in rat

目的研究载脂蛋白M(apoM)在大鼠体内的清除及分布。方法用125I标记重组apoM,注入大鼠尾静脉,于不同时间点取血及各个器官,研究apoM在大鼠体内的清除和分布。结果125I-apoM的标记率为98%,大鼠血液中清除过程曲线符合二房室开放型模型,分布相半衰期T1/2(α)=0.485h,消除相半衰期T1/2(β)=9.680h,分数清除率(FCR)=11.960/h。apoM在大鼠组织和器官的分布用每克组织放射性表示,胃分布最高,小肠、肝、肺、肾分布次之,脑分布最低,且每克组织放射性随时间增加逐渐降低。将每克组织放射性换算成总组织放射性时,小肠最高,胃和肝次之。结论ApoM在大鼠血液中清除过程曲线符合二房室开放型模型,在血液中FCR=11.960/h。125I-apoM主要在胃、小肠和肝被结合摄取,小肠、胃和肝可能存在结合及摄取125I-apoM的结合位点,胃、小肠及肝脏可能是参与apoM代谢的重要器官,存在着apoM的受体。

Objective In this study,we investigated metabolism and distribution of apolipoprotein M in rat. Methods Metabolism and distribution of apoM in vlvo was studied by injecting purified ^125I-labeled apoM into the circulation of the animals through a tail vein and then taking periodic blood samples and different organs. Results The results showed that concentration-time curves after the venous injection of ^125I- labeled were fitted to a two-compartment model of pharmacokinetics. T1/2 （α） =0. 485 h, T1/2 （ β ） = 9. 680 h, FCR = 11. 960/h. The radioactivity in different organs after the venous injection of ^125I-apoM showed that the stomach contained higher radioactity than that in other organs. Conclusions In the present study, we demonstrate that the concentration-time profile after the venous injection of ^125 I-apoM was described by a two- compartment model. There might be some specific binding sites for apoM in stomach. It is possible that stomach is a novel target organ.