心肌显像剂^(99)Tc^mN(NOEt)_2动物药理实验和再分布特性

A study on pharmacology and redistribution of a myocardial imaging agent ^(99)Tc^mN(NOEt)_2

目的 对心肌显像剂99Tcm 氮 二 (N 乙基 N 乙氧基二硫代氨基甲酸盐 ) [N(NOEt) 2 ]进行临床前药理实验和再分布特性研究。方法 制备的99TcmN(NOEt) 2 放化纯度 >95 % ,对 5只实验犬进行了血药动力学、体内生物分布和显像、99TcmN(NOEt) 2 和2 0 1 Tl缺血心肌再分布显像对比和毒性的研究。结果 99TcmN(NOEt) 2 的放化纯度平均为 (98 41± 0 46 ) % ,血清除T(α) 1 2 =(2 8± 0 1)min ,T(β) 1 2 =(142 7± 32 7)min ,总清除速率Cl=(2 92 3± 117 1)mL h。显像示99TcmN(NOEt) 2 能被心肌较快地摄取 ,肺中摄取清除快速 ,肝摄取较高。在 10、30、6 0、90、12 0min时 ,心肌摄取为 (4 2 7± 0 2 1)、(5 3±1 48)、(5 3± 0 6 6 )、(4 0± 0 5 3)和 (3 6 7± 0 35 ) %ID ;心 肺和心 肝比值分别是 1 2 4± 0 31、2 0 3±0 45、2 33± 0 31、2 2 3± 0 5、2 0 7± 0 49和 0 94± 0 0 8、0 78± 0 15、0 5 6± 0 2 2、0 5 3± 0 2 2、0 38±0 15。在 30和 6 0min时心肌影像最为清晰。99TcmN(NOEt) 2 在犬缺血心肌中有再分布特征 ,并与2 0 1 Tl的再分布显像自身对照结果一致。结论 99TcmN(NOEt) 2 是很有价值的心肌灌注显像剂 ,并有与2 0 1 Tl一样的再分布特征。

Objective To study the biological properties of the myocardial imaging agent 99 Tc mN(NOEt)_2 and compare its redistribution characters with 201 Tl. Methods The 99 Tc mN(NOEt)_2 was prepared. Blood clearance, biodistribution, imaging and redistribution imaging with 99 Tc mN(NOEt)_2 or 201 Tl were studied in 5 dogs. Results Radiochemical purity of 99 Tc mN(NOEt)_2 was (98.41±0.46)%,blood clearance T (α)_ 1/2 =(2.8±0.1) min, T (β)_ 1/2 =(142.7±32.7) min,Cl=(292.3±117.1) mL/h.Imaging studies demonstrated that 99 Tc mN(NOEt)_2was distributed rapidly in the myocardium of the dogs, disappearance of pulmonary uptake was faster than that of myocardial uptake, the uptake was higher in liver. At 10,30,60,90 and 120 min after injection the myocardial uptakes were (4.27±0.21),(5.3±1.48),(5.3±0.66),(4.0±0.53) and (3.67±0.35)%ID;the heart-to-lung ratios and the heart-to-liver ratios of these time points were 1.24±0.31,2.03±0.45,2.33±0.31,2.23±0.5,2.07±0.49,0.94±0.08,0.78±0.15,0.56±0.22,0.53±0.22,0.38±0.15, respectively, the myocardial images were most distinct at 30 and 60 min postinjection. The results of redistribution in ischemic myocardium of dogs with 99 Tc mN(NOEt)_2 or 201 Tl were about the same. Conclusion 99 Tc mN(NOEt)_2 is very worth to be one of the new myocardial imaging agents, it has the redistributive character just as that of 201 Tl.