【論文摘要】Synthesis and Imaging Evaluation of Gastro-Resistant Insulin Receptor-Binding Peptide in the Diabetic Mice

Jyun-Hong Chen ； Po-Jung Chen ； Mao-Chi Weng ； Mei-Hui Wang

《核子醫學暨分子影像雜誌》 32卷1期 (2019/03) Pp. 37-37

https://doi.org/10.6332/ANMMI.201903.OB2

摘要

Introduction: Diabetes is characterized by hyperglycemia, which is caused by a defect in insulin secretion, insulin resistance, or a combination of both. Gastro-Resistant Insulin Receptor-Binding Peptides (IRBP) have insulin receptor-binding and blood glucose-lowering activities. And Gastro-Resistant characteristic was suitable for oral use. Peptide synthesis and imaging evaluation experiments in type 1 and type 2 diabetic mice could be helpful for drug development. Methods: We developed the IRBP peptide synthesizing under a variety of conditions by using the CEM Liberty automated microwave peptide synthesizer. The bifunctional chelating agent S-2-(4-isothiocyanatobenzyl)-diethylenetriamine pentaacetic acid (p-SCN-Bn-DTPA) was linked to the peptide and labelled with In-111. DTPA-IRBP peptides were purified by high-performance liquid chromatography (HPLC) and confirmed by mass spectrometry (MS) and micro-single photon emission computed tomography/computed tomography (microSPECT/CT) imaging was performed in normal, type 1, and type 2 diabetic mice. Results: The purity of DTPA-IRBP peptide was ＞ 95%. Before microSPECT imaging test, stability of In-111-DTPAIRBP peptide was evaluated in normal mice serum and in phosphate-buffered saline (PBS) at 37°C and stable during 4 h. After oral injection of In-111-DTPA-IRBP peptide (500 μCi) for 20 min, the mice were detected by microSPECT/CT. The accumulation activity in gastro-intestinal tracts was evaluated. Conclusions: The IRBP peptide was successfully synthesized by CEM Liberty peptide synthesizer and p-SCN-Bn-DTPA was linked to IRBP peptide successfully. In-111-DTPA-IRBP peptide is produced with high yield and stability. The initial imaging test also showed good stability in diabetic mice and longer duration biodistribution evaluation may be needed.