新型心肌灌注显像剂^(99)Tc^m-CO-MIBI与^(99)Tc^m-MIBI的药理学比较

Pharmacological Study of ^(99)Tc^m-CO-MIBI,a New Myocardial Perfusion Imaging Agent Comparison to ^(99)Tc^m-MIBI

以犬为实验动物,99Tcm-CO-MIBI和99Tcm-MIBI为显像剂,采用自身对照的方法,通过采集血样、采集动态图像和全身显像获得药物在犬体内的代谢动力学参数、生物分布、靶与非靶放射性摄取比和全身、心脏平面及断层影像等药效学结果。结果显示,99Tcm-CO-MIBI符合一次静脉给药的血药动力学二室开放模型,快相及慢相半衰期分别为Tα(1/2)=1.46±0.13 min,Tβ(1/2)=97.30±20.50 min,全血总清除率CL=436.36±54.77 mL/h。心、肺、肝时间-放射性曲线显示,在注射约40 min后,99Tcm-CO-MIBI肝脏曲线明显低于心肌曲线。多时间点心脏与肺脏及肝脏的放射性摄取比亦表明99Tcm-CO-MIBI在心肌摄取高,滞留久,肺本底低,肝脏药物排出比99Tcm-MIBI明显快。注射99Tcm-CO-MIBI后10~120 min内均可获得清晰的心肌图像,40 min后下壁心肌显示不再受肝内放射性干扰。表明99Tcm-CO-MIBI犬体内生物分布优异,有望成为一种新型心肌灌注显像剂。

Pharmacological experiment of ^99Tc^m-MIBI and ^99Tc^m-CO-MIBI are performed by self-contrast in dogs. The data of pharmacokinetics parameters, biodistribution, T/NT are collected and calculated during and after photograph. Moreover, the whole body image, heart plane scintigraphy and tomography are investigated. Blood-pool clearance of ^99Tc^m-CO-MIBI conforms to two-compartment with 436.36±54.77 mL/h of blood clearance （CL） and Tα（1/2） ：1.46±0.13 min for the fast early clearance, Tβ（1/2 ：97.30±20.50 min for the slow late clearance, which faster than that of ^99Tc^m-MIBI. The time-radioactivity curves show that the hepatic uptake curves are below the heart curves at about 40 rain after ^99Tc^m- CO-MIBI injecting. The heart-lung and heart-liver ratios, which are measured at several time points, also demonstrate that ^99Tc^m-CO-MIBI have higher uptake and longer retain in myocardium, lower lung radioactivity and faster excrete from liver compare to 99 Tcm MIBI. During 10-120 min after ^99Tc^m-CO-MIBI injected, the excellent plane and SPECT can be obtained , perfect myocardial image without liver activity disturbance are gained after 40 min injecting. It suggests that ^99Tc^m-CO-MIBI have better pharmacokinetics properties and offer a great possibility as a new myocardial perfusion image agent.