Direct effect of glucagon-like peptide-1 on the autoregulatory response of the afferent arteriole (692.2)

It has become clear that glucagon-like peptide-1 (GLP-1) has many effects and the GLP-1 receptor is expressed in many tissues outside the pancreas. GLP-1 increases renal blood flow (RBF), glomerular filtration rate and sodium and water excretion. The aim of this study was to examine expression of the GLP-1 receptor in the renal vasculature and assess the effects of GLP-1 in the afferent arteriole. The GLP-1 receptor was localized using 125I-GLP-1 in kidney slices. In the isolated juxtamedullary nephron preparation, renal perfusion pressure was increased in steps and changes in afferent arteriolar diameter were measured before and after perfusion with GLP-1. In vivo experiments were performed on rats monitoring blood pressure (BP), RBF and urine flow. GLP-1 was infused directly into the kidney before and after infusion of the GLP-1 receptor blocker Exendin9-39 and indomethacin and L-NAME.Strong binding of 125I-GLP-1 was found in the vascular smooth muscle cells in afferent arterioles. Perfusion with GLP-1 ...