^99Tc^m-环丙沙星炎症显像的动物实验研究

Experimentai imaging study of ^99Tc^m-dprofloxacin in detection of infection

目的用^99Tc^m标记环丙沙星并评估其生物学性能。方法制备^99Tc^m-环丙沙星，测定其稳定性，并研究其在健康昆明小鼠体内和在炎症模型昆明小鼠及新西兰兔体内的分布。结果^99Tc^m-环丙沙星标记率〉90％，6h内放化纯均〉98％。^99Tc^m-环丙沙星静脉注射后主要分布在血供丰富的器官，如肾、肝、脾中。血液清除陕，主要经泌尿系统排泄。新西兰兔炎症模型显像表明：注射^99Tc^m-环丙沙星1h后即可显影；给药后3h为炎症小鼠模型最佳显像时间，此时炎症组织／肌肉放射性比值为5．76。^99Tc^m-环丙沙星能高度特异地浓聚于细菌性炎症病灶。结论^99Tc^m-环丙沙星是早期诊断细菌性炎症的一种特异性显像剂，其临床应用前景较好。

Objective Most of the current imaging agents for inflammatory and（or） infectious diseases are not speciiic enough. It was studied that using ciprofloxacin （an antibiotics）labeled with ^99Tc^m- for a novel imaging agent detected inflammatory and（or） infectious loci ia vivo. Methods In this investigation, the biological properties were evaluated by pharmacologic experiments. The end points of this study were two. One was to study the biodistribntion of ^99Tc^m-labeled ciprofloxacin（ an antibiotics）ia vivo. The other was to understand the potential role of ^99Tc^m-ciprofloxacin in detecting inflammatory and（or） infectious loci in rabbit models. The biodistribution of ^99Tc^m-ciprofloxacin was studied in mice models. Scintigraphy of ^99Tc^m-ciprofloxacin was performed in rabbit models. Results The labeling rate was over 90%. The dissociation of ^99Tc^m-ciprofloxacin was minimal within 8 h at room temperature. After intravenous injection, rapid plasma clearance and renal clearance were observed. Kidney, liver and spleen were the target organs for the accumulation of injected ^99Tc^m--ciprofloxacin. In the infectious rabbit models （ a= 3 ）, accumulation of ^99Tc^m-ciprofloxacin was found at the infective lesion （left thigh）. The dynamic study showed that the optimal acquisition time for ^99Tc^m-ciprofloxacin imaging was at 3 h after injection. Moreover, images could still be positive at 24 h after injection. Notably, little 99Tc^-ciprofloxacin accumulation was observed at the inflammation foei in above rabbit models. Conclusion ^99Tc^m-eiprofloxacin could be a potential imaging agent for infectious rather than inflammatory disease ia vivo in the future.