Fig. 2

Role of K⁺ on rhythmic contractions in rat aortic rings. Original tracings showing the effect of different doses of KCl (10–30 mM) (a) or effect of K⁺ channel blockers alone (5 mM BaCl₂ or 5 mM of TEA) (b). Vasoconstriction occurred just when the K⁺ channel blocker was added alone to the bath; but rhythmic contractions were only observed with TEA. The arrows indicate when the KCl, BaCl₂ or TEA was added to the bath