四种^(99m)Tc标记的乙撑-双(半胱胺酸酯)生物效应比较

A comparative study of the biological properties of four ^(99m)Tc-labelled L, L-alkyl-cysteinate dimers

本文对四种不同长度碳链烷基酯ECD[N,N′-乙撑-双(L-半胱胺酸乙酯)]衍生物的生物效应进行了比较,研究结果表明,烷基碳链的长度与它们各自的脂溶性、血浆蛋白(HSA)的结合率、脑摄取量呈正相关,但与脑清除速度呈负相关。注射后10s,^(99m)Tc-MCD、^(99m)Tc-ECD、^(99m)Tc-PCD和^(99m)Tc-BCD在大鼠脑的浓度(％I.D/g)分别为0.45、0.59、0.96和0.68。由猴的全身显像所见,注药后1.5h脑药物浓度分别为1.3、3.1、3.2和2.2(％I.D),肝内的放射性浓聚最高,经代谢有较大部分由肾排出。

Four 99mTc-ECD derivatives with different alkyl ester were prepared from corresponding precursors by ligand exchange reactions. The pharmacological properties of these complexes were studied and compared. There are positive correlations between the protein-binding rate and the lipophilicity of the complexes. Biodistribution studies in rats demonstrated that complexes with high lipophilicity also have high concentration and low clearance. The brain uptake in rats 10 seconds after injection was 0.45,0.59, 0.96 and 0.68 (%I. D/g) for 99mTc-MCD, ECD, PCD and BCD respectively. Whole body imaging studies in mon-keys showed that the activity of brain was 1.3, 3.1, 3.2 and 2.2% for each complex 1.5h after injection. The activity was the highest in liver and most of the activity was excreted Via kidney.