Abstract 17020: Molecular Spect Imaging of Early Angioproliferative Group I Pulmonary Arterial Hypertension Using an Adrenomedullin Receptor Ligand

Introduction: The main limitation in the development of drugs against pulmonary arterial hypertension (PAH) is the absence of a non-invasive and early marker of disease. Adrenomedullin (AM) is a vasodilator peptide predominantly cleared by pulmonary endothelial receptors. Hypothesis: Our lab has developed Pulmobind "PB", an AM derivative radiolabeled with 99mTc for SPECT imaging of pulmonary circulation to detect non-invasively the anomalies of pulmonary circulation caused by PAH. Methods: An angioproliferative model of group I PAH was used. After a single subcutaneous injection of the vascular endothelial growth factor receptor blocker "Sugen" (20 mg/kg), rats were exposed to hypoxia for 3 weeks followed by normoxia for 4 weeks. PAH rats were compared to their littermate controls (normoxia for 7 weeks). After 7 weeks, Right ventricular (RV) structure, function and hypertrophy as well as lung 99mTc-PB uptake kinetics were assessed by echocardiography and SPECT analyses. Results: RV end-diastolic anterior ...