This study aimed to seek necrosis avid agents with high safety from DNA binding agents. The interaction of 5-hydroxytryptophan(5-HTP) with DNA was investigated by a series of spectroscopic studies. Then, 5-HTP was lab...This study aimed to seek necrosis avid agents with high safety from DNA binding agents. The interaction of 5-hydroxytryptophan(5-HTP) with DNA was investigated by a series of spectroscopic studies. Then, 5-HTP was labeled with iodine-131([^(131)I]5-HTP) and the necrosis avidity of [^(131)I]5-HTP was evaluated by in vitro cell binding assays, in vivo biodistribution experiments and blocking experiment. Finally, the potential of [^(131)I]5-HTP to image necrotic myocardium was explored in rat models with myocardial infarction by SPECT/CT imaging. Results showed that 5-HTP bound to DNA in groove binding mode and the binding constant was 1.69×10~4 L/mol. [~(^(131))I]5-HTP showed specific affinity to necrotic A549 cells,which might be related to cell nucleus. Biodistribution and autoradiography results showed preferential accumulation of [^(131)I]5-HTP in necrotic muscle(necrotic/viable muscle ratio: 6.95 ? 0.68 at 3 h postinjection(p.i.)), which could be blocked by 5-HTP with 66.7% decline, indicating that [^(131)I]5-HTP might share the same necrotic targets with 5-HTP. On SPECT/CT images, a hotspot was clearly observed at 3h p.i.in the necrotic myocardium while not in the control myocardium. In conclusion, [^(131) I]5-HTP is a novel necrosis avid agent and can rapidly visualize necrotic myocardium at 3 h p.i. The necrosis avidity mechanism of [^(131) I]5-HTP may be attributed to its interactions with exposed DNA in the necrotic tissues.展开更多
基金partially supported by the National Natural Science Foundation of China (Nos. 81473120, 81501536, 81473120)
文摘This study aimed to seek necrosis avid agents with high safety from DNA binding agents. The interaction of 5-hydroxytryptophan(5-HTP) with DNA was investigated by a series of spectroscopic studies. Then, 5-HTP was labeled with iodine-131([^(131)I]5-HTP) and the necrosis avidity of [^(131)I]5-HTP was evaluated by in vitro cell binding assays, in vivo biodistribution experiments and blocking experiment. Finally, the potential of [^(131)I]5-HTP to image necrotic myocardium was explored in rat models with myocardial infarction by SPECT/CT imaging. Results showed that 5-HTP bound to DNA in groove binding mode and the binding constant was 1.69×10~4 L/mol. [~(^(131))I]5-HTP showed specific affinity to necrotic A549 cells,which might be related to cell nucleus. Biodistribution and autoradiography results showed preferential accumulation of [^(131)I]5-HTP in necrotic muscle(necrotic/viable muscle ratio: 6.95 ? 0.68 at 3 h postinjection(p.i.)), which could be blocked by 5-HTP with 66.7% decline, indicating that [^(131)I]5-HTP might share the same necrotic targets with 5-HTP. On SPECT/CT images, a hotspot was clearly observed at 3h p.i.in the necrotic myocardium while not in the control myocardium. In conclusion, [^(131) I]5-HTP is a novel necrosis avid agent and can rapidly visualize necrotic myocardium at 3 h p.i. The necrosis avidity mechanism of [^(131) I]5-HTP may be attributed to its interactions with exposed DNA in the necrotic tissues.
