不同比活度11C-氟马西尼体内代谢的差异分析

目的 通过测定¹¹C-氟马西尼（¹¹C-flumazenil，¹¹C-FMZ）在体内主要代谢物的百分占比，分析不同比活度¹¹C-FMZ的代谢差异。方法 选取2019年5月至10月10名受试者，其中，男性5名，女性5名，平均年龄（41.7±4.7）岁，平均体重（69.3±6.8）kg。先后注射高低两种比活度（268.3±57.2）×10³和(57.8±11.4)×10³Ci/mol的¹¹C-FMZ，并分别测定注射后1、2、3、4、5、10、15、20、30、40、60 min时血浆中¹¹C-FMZ及其代谢物的百分注射剂量率，使用配对样本均数t检验计算并对比两组代谢物的百分占比。结果 代谢物的百分占比随时间逐步增加，于15 min后基本趋于稳定，且低比活度组的百分占比明显高于高比活度组，在15～60 min的区间存在显著统计学差异（P<0.05）。结论 不同比活度的¹¹C-FMZ注射后的代谢率存在明显差异，临床应用时应尽量避免比活度差异过大。

The metabolic analysis of 11C-flumazenil in different specific radioactivity

Objective To analyze the metabolic differences of ¹¹C-flumazenil (¹¹C-FMZ) with different specific radioactivity by detecting the percentage proportion of the main metabolites in vivo.Methods 5 male and 5 female volunteers with average age of (41.7±4.7) years and weight of (69.3±6.8) kg were selected from May to October 2019. ¹¹C-FMZ with high and low specific radioactivity (268.3±57.2)×10³ and (57.8±11.4)×10³ Ci/mol was injected successively. The percentage of injected dose/liter of ¹¹C-FMZ and its metabolites in the plasma at 1, 2, 3, 4, 5, 10, 15, 20, 30, 40 and 60 min after the injection was measured. Paired sample mean t test was used to calculate and compare the percentage of metabolites in the two groups.Results The percentage proportion of metabolites increased gradually with time, and reached the stable level after 15 min. The percentage proportion of low specific radioactivity group was higher than that of high specific radioactivity group with a significant statistical difference between 15 min and 60 min (P<0.05).Conclusion The metabolic rate of ¹¹C-FMZ with different specific radioactivity was significantly different after injection and the specific radioactivity difference should be avoided if possible in clinical application.