Imaging of glucagon-like peptide-1 receptor expression after experimental myocardial infarction with 68Ga-NODAGA-Exendin-4

348 Objectives Glucagon-like peptide-1 receptor (GLP-1R) is expressed in the heart and may have cardioprotective effects. We evaluated 68Ga-NODAGA-Exendin-4 for monitoring the level of GLP-1R expression in the heart after experimental myocardial infarction (MI). Methods Rats were studied at 1 wk (n=7) and at 12 wk (n=6) after induction of MI by permanent ligation of the left coronary artery or at the same time-points after sham-operation (n=9 and n=5, respectively). After 54±3 MBq injection of 68Ga-NODAGA-Exendin-4, 60 min dynamic PET and contrast-enhanced CT were performed. After imaging, left ventricle (LV) was cut into serial short axis cryosections for autoradiography, histology and immunohistochemistry. Results Average MI size measured as percentage of LV circumference was 42±7 % at 1 wk and 37±14 % at 12 wk. In vivo imaging showed 68Ga-NODAGA-Exendin-4 uptake at the infarcted anterior wall of the LV. Compared with the myocardium of sham-operated rats, autoradiography showed increased (p Conclusions 68Ga-NODAGA-Exendin-4 detects increased myocardial GLP-1R expression extending to 3 months after MI. Imaging of GLP-1R may help to study the functions and therapeutic potential of incretins in the heart.