Figure 6.

Effects of the anionic blocker SITS on the HCO₃⁻-induced changes in APD A, representative traces of APs recorded from a myocyte exposed successively to Hepes, HCO₃⁻ (10 min) and HCO₃⁻+ SITS (0.1 mm) (10 min). B, average values of APD₅₀ obtained from six myocytes subjected to the conditions of A. C, representative traces of APs recorded from a myocyte exposed successively to Hepes, Hepes + SITS (0.1 mm) (10 min) and HCO₃⁻+ SITS (0.1 mm) (10 min). D, average values of APD₅₀ obtained from six myocytes subjected to the conditions of C. The APD shortening induced by 20 mm HCO₃⁻ was reversed and prevented by 0.1 mm SITS. *Significantly different from Hepes.