摘要
目的确立^(131)I标记胰高血糖素样肽-1(GLP-1)受体激动剂exendin-4多肽的最佳标记条件,并研究^(131)I-exendin-4在正常小鼠体内的生物分布。方法^(131)I标记exendin-4多肽采取氯胺-T方法标记,利用纸层析法计算标记产物的标记率及放化纯度,测定^(131)I-exendin-4的体外稳定性及脂水分配系数,研究^(131)I-exendin-4在注射后的1、3、6、12和24 h时在正常小鼠体内的分布特征,对经尾静脉注入^(131)I-exendin-4的小鼠进行SPECT多时相显像,并观察小鼠体内放射性分布变化。结果 exendin-4的^(131)I标记率在85%以上,放化纯度大于97%,^(131)I-exendin-4在人血清和生理盐水中仍保持较好的体外稳定性,^(131)I-exendin-4的脂水分配系数为-1.002。正常小鼠静脉注入^(131)I-exendin-4后,双肾的放射性分布明显较其他组织器官的放射性增高,1 h和12 h肾脏的每克组织百分注射剂量率(%ID/g)分别为(51.54±13.51)%ID/g和(11.61±0.94)%ID/g,胃、肺的摄取相对较高,3 h后除肾脏外的其他各脏器器官的放射性均较快下降。正常小鼠静注^(131)I-exendin-4后的SPECT多时相显像示随着时间的延长,双肾及膀胱的放射性浓聚影增加,而其他器官未见明显放射性浓聚影分布。结论^(131)I标记exendin-4的标记率较高(大于85%),体外稳定性良好,^(131)I-exendin-4为水溶性物质,可通过泌尿系统排泄,体外分布特性比较理想。
Objective To establish the radiolabeling method of exendin4, an glucagon-like peptide 1 ( GLP-1 ) receptor agonist, with 131I and observe the biodistribution of 131I-exend in4 in normal mice. Methods Radiolabeling of exendin- 4 with 131I was performed by chloramine-T method. The labeling ratio and radiochemical purity were determined using pa- per chromatography and TLC. The octanol-water partition coefficient and stability in vitro in saline and normal human ser- um of labeled polypeptide were also determined. The biodistribution of 131I-exendin-4 in normal mice were measured at 1, 3, 6, 12, 24 h after intravenous injection. SPECT was performed in 3 male mice after injection of 131I-exendin4 to ob- serve the dynamic distribution of the labeled exendin4. Results The labeling yield of 131I-exendin4 was more than 85%. The 131I-exendin4 had good stability in saline and normal human serum. The octanol-water partiton coefficient lg P = - 1. 002. The biodistribution in mice showed that 131I-exendin4 had rapid blood clearing, and the radioactivity in kidney was obviously higher than that of other organs as indicated by their uptake of (51.54 ± 13.51 ) % ID/g at 1 h and (11.61 ±0.94)% ID/g at 12 h, respectively. Organs such as stomach, lung, intestine and bone had transient radioac- tive uptake, and then after 3h the radioactivity in those organs rapidly decreased. The radioactivity in other organs always kept at a low level. Conclusion 131I-exendin4 can be easily labeled with a high labeling ratio with stability in vitro. It has good distribution characteristics in vivo, and is cleared mainly by renal excretion due to its hydrosolubility.
作者
江英
齐永帅
黄宝丹
黄凯
池晓华
李贵平
JIANG Ying, QI Yong-shuai, HUANG Bao-dan, et al(Department of Nuclear Medicine, Nanfang Hospital of Southern Medical University, Guangzhou , Guangdong 510515, Chin)
出处
《中华全科医学》
2018年第4期529-532,662,共5页
Chinese Journal of General Practice
基金
广东省科技计划项目(2014A020212181)
广州市科技计划项目(201607010230)