Figure 3.

Pharmacological characterization of K⁺-induced relaxation. Original tracing in an endothelium-intact ring of interlobar artery (a) and statistical summary (b) showing the relaxant effect of the cumulative addition of KCl on the tone of arterial rings preconstricted with U46619 (U, 80 nM). Experiments were performed using endothelium-intact (E+) and endothelium-denuded (E-) rings. (c) Effect of the combination of charybdotoxin and apamin (Cbtx/Apa, each 100 nM) and ouabain (OU, 100 nM) on the KCl (10 mM; 14 mM final bath concentration)-induced relaxation of endothelium-denuded arterial rings, preconstricted with U46619 (80 nM). (d) Effect of nifedipine (1 μM) on the relaxation of U46619-contracted arterial rings induced by the cumulative addition of KCl. Presented are the mean±s.e.mean of six separate experiments.