Effect of a 2-Adrenoceptor Stimulation on Hyperglycemia- Induced Endothelial Dysfunction

To investigate whether 2-adrenoceptors exist on endothelial cells and whether a 2-adrenoceptor stimulation might prevent the development of hyperglycemia-induced endothelial dysfunction, porcine aortic endothelial cells (PAECs) were cultured and chron-ically exposed to either 5 mM D-glucose (“normoglycemia”) or 20 mM D-glucose (“hyperglycemia”), with or without 100 nM salbu-tamol in absence or presence of 2-adrenoceptor antagonist ICI 118,551 [1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxyl]-3-[(1-methylethyl)-amino]-2-butanol] or 1-antagonist metoprolol. For osmotic control, PAECs were exposed to 15 mM L-glucose. We measured nitric oxide release using the met-hemoglobin assay and assessed -adrenoceptor density and subtypes by radioli-gand binding. Furthermore, we determined intracellular NADH and NADPH using high-performance liquid chromatography. High D