摘要
为评价生物素-亲和素预定位技术在炎症显像中的应用价值,采用链霉亲和素(SA)和^(113m)In-DTPA-生物素(^(113)In-DB)、生物素-人免疫球蛋白(B-hlgG)和^(131)I-链霉亲和素(^(131)I-SA)行二步法预定位炎症显像,并以^(99m)Tc 直接标记hlgG、SA 一步法显像为对照,于2、6或24小时显像,测定生物分布。实验动物用葡萄球菌所致小鼠炎症模型。结果:SA和^(113m)In-DB 二步法预定位法在2小时即可显像,其靶/非靶(T/NT)比值为1.83,6小时达4.33,血中清除较快;B-hlgG和^(131)I-SA 二步法预定位显像,T/NT 在2小时仅0.39,24小时升至2.70,hlgG 血中清除时间较长,血本底较高。直接标记SA 在肝、肾有较多放射性浓聚;标记 hlgG 分子量较大。其血清除时间长,6小时仍保持较高水平,且肝积聚较多,图像不清晰。结果表明,预定位法的 T/NT 比值较直接标记蛋白质法为高,且显像时间提前;可用于炎症显像,并可提高图像的清晰度。
PURPOSE To evaluate the usefulness of biotin-avidin pretargeting technique in inflammation imaging.METH- ODS A two-step method was used.6 hours after a preinjection of biotin-hIgG (B-hIgG) or streptavidin (SA),^(131)I-SA or ^(113m)In- DTPA-biotin(^(113m)In-DB) was injected.2h,6h or 24h later,γ-image was performed and biodistribution was studied.^(99m)Tc- hIgG,a one-step method using ^(99m)Tc-SA,was used as control.An animal model was caused by staphlococci.RESULTS B-hIgG and ^(131)I-SA two-step method:T/NT was only 0.39 at 2h and reached 2.70 at 24h.In γ-imaging,no concentration of radioactivi- ty was found in inflammatory site at 2h,6h and 24h.Because it took a long time to clear hIgG in blood,the blood background was higher,SA and ^(113m)In-DB two-step method:in γ-imaging,concentration of radioacitivity was observed in inflammatory site as early as 2h,T/NT was 1.83 at 2h and 4.33 at 6h.^(99m)Tc-hIgG,^(99m)Tc-SA one-step method:SA,as a kind of protein,could con- centrate in inflammatory site,but high concentration of radioacitivity was also visualized in liver and spleen.Owing to high molecule weight,labelled hIgG not only maintained a higher level in blood,but also accumulated in liver,hence the imaging quali- ty wasn't satisfied.CONCLUSIONS The biotin-avidin pretargeting technique can attain a higher T/NT ratio than the one-step method and a low blood background so as early imaging can be got with better imaging quality.
出处
《中华核医学杂志》
CAS
CSCD
北大核心
1996年第3期191-192,共2页
Chinese Journal of Nuclear Medicine
关键词
炎症
放射性核素显像
生物素
亲和素
Inflammation
Radionuclide imaging
Biotin-avidin
Mice
