Action of the NO donor SNP and effect of the GC inhibitor ODQ on EFS-evoked hyperpolarization in the longitudinal smooth muscle of the chicken mesenteric artery. Typical recordings of membrane response after exogenous application of the NO donor SNP (10 µM) in endothelium-intact (A) and endothelium-removed (B) preparations are shown. (C) Typical recordings of EFS-evoked responses in the absence (control) or presence of ODQ (10 µM) are shown. Similar results were obtained in five independent experiments. EFS, electrical field stimulation; NO, nitric oxide; ODQ, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one.