The purpose of this study is to characterize the tissue distribution, excretion and pharmacokinetics profiles of R-hap in healthy Wistar rats. R-hap was radiolabeled by the IODO-GEN method. Tissue distribution and urinary, fecal and biliary excretion patterns of ^125I-R-hap were investigated following a single i.v. bolus injection. Pharmacokinetics properties of ^125I-R-hap were also examined after a single i.v. bolus injection. The trichloroacetic acid （TCA） precipitated radioactivity was widely distributed and rapiclly diminished in most tissues. Kidney contained the highest radioactivity among all organs and the distribution of ^125I-R-hap to fat was minimal. The cumulative excretion of ^125I-R-hap reached 71.81% ± 2.15% of the administered radioactivity at 48 h and 94.71% ± 1.50% at 120 h. Urinary excretion was the dominant route of elimination following i.v. administration, as 80.64% ± 1.47% and 14.07% ± 0.95% of administered radioactivity were recovered in urine and feces, respectively, in intact rats over 120 h. The mean areas under the plasma concentration-time curve was （8818.4 ± 576.1） Bq/h/mL. The results of tissue distribution, excretion and pharmacokinetics of R-hap in rats provided biopharmaceutical basis for the design of future clinical trials.
目的探讨^(99)Tc^m 直接标记带有10个连续组氨酸的膜联蛋白 V(Annexin V)衍生物的可行性,研究其在健康小鼠体内的分布和肺癌裸鼠模型凋亡显像。方法直接标记法制备^(99)Tc^m-Annexin V 衍生物,并测产物放化纯、胶体含量及健康小鼠体内不同时间点(5,30 min 和1,2,4,6,12,24 h)的生物分布,DAS 2.0软件拟合计算药代动力学参数。建立荷 H460非小细胞肺癌裸鼠模型,分为紫杉醇诱导化疗组(5只)和未治疗对照组(5只)。紫杉醇诱导化疗后48 h,于裸鼠尾静脉注射^(99)Tc^m-Annexin V 衍生物18.5 MBq,2和4 h 时进行凋亡显像,勾画 ROI 并计算肿瘤与对侧正常组织(T/NT)放射性比值。结果放化纯达(98.01±1.67)%,3 h 后放化纯仍可达(95.45±1.34)%,胶体含量为(3.31±1.37)%。健康小鼠体内分布实验表明肾脏对该示踪剂摄取最高,肝、脾摄取较少。DAS 2.0软件拟合得到时间-放射性曲线符合二室模型特征,分布相半衰期(T_(1/2α))为(21.18±5.95)min,清除相半衰期(T_(1/2β))为(69.32±0.10)min。荷瘤鼠显像示,给药后2 h 即可获得清晰的图像,紫杉醇诱导化疗组2和4 h 的 T/NT 比值为3.85±1.10和4.63±0.97,明显高于对照组(1.60±0.29和1.71±0.43,P<0.01)。结论该Annexin V 衍生物易于^(99)Tc^m直接标记,方法简便,标记物在血液中清除迅速,肝、脾摄取少,易得到高清晰图像。
