No abstract

aÃPeptides are known as receptor-specific molecules that play an important role not only in diagnosis and therapy of neoplastic diseases, but also in the pathogenesis of other diseases. In an effort to develop a peptide-based radiopharmaceutical for scintigraphic studies, a small peptide Tyr-Gly-Gly-Ser-Leu-Ala-Lys (YGGSLAK) was synthesized by Fmoc solid-phase peptide synthesis using an automated synthesizer. This peptide was analyzed by TLC, HPLC and mass spectroscopy. Then, we investigated its analytical and pharmacokinetic study after radiolabeling with technetium-99 m ( 99m Tc) using SnCl 2 . The radiochemical purity of the complex was over 95% and log p value was 1.46. In vivo biodistribution studies in rat showed that most activity of this injected radiolabeled peptide ( 99m Tc-YGGSLAK) was accumulated in the liver and followed by gallbladder, intestines and kidney. Scintigraphy studies on rabbits also showed very high uptake and retention in the liver and gallbladder, and after 1 h slowly excreted through the hepatobiliary system and a little amount was also excreted through the renal system. The radiochemical and in vitro and in vivo characterization indicates that 99m Tc-YGGSLAK has certain favorable properties and it might be used as a new radiopharmaceutical for hepatobiliary scintigraphy.