The anodal SI curves after other pharmacological interventions. A, Before (broken lines) and after (solid lines) infusion of low Na. Anodal dip disappeared after low Na. B, Thapsigargin (Thap, 3 μmol/L). C, Ryanodine (Ryd, 3 μmol/L). D, Ryanodine (3 μmol/L) and thapsigargin (3 μmol/L). Asterisks indicate anodal dip.