64Cu- and 68Ga-Labelled [Nle14,Lys40(Ahx-NODAGA)NH2]-Exendin-4 for Pancreatic Beta Cell Imaging in Rats

Glucagon-like peptide-1 receptor (GLP-1R) is a molecular target for imaging of pancreatic beta cells. We compared the ability of [Nle14,Lys40(Ahx-NODAGA-64Cu)NH2]-exendin-4 ([64Cu]NODAGA-exendin-4) and [Nle14,Lys40(Ahx-NODAGA-68Ga)NH2]-exendin-4 ([68Ga]NODAGA-exendin-4) to detect native pancreatic islets in rodents. The stability, lipophilicity and affinity of the radiotracers to the GLP-1R were determined in vitro. The biodistribution of the...