Figure 5. Resting potassium and chloride conductance of Sol and EDL muscle fibers of wild-type and PTN-overexpressing mice after 14 days HU.

A) The chloride and potassium conductance of sarcolemma at rest were measured in current-clamp mode with the two-intracellular microelectrodes technique. Each bar is the mean conductance ± SEM calculated from 16-to-53 muscle fibers of 3-to-6 mice. Statistical analysis performed with unpaired Student’s t test indicates significant change (P<0.05) versus WT-G (*), WT-HU ($), and PTN-G (#). B) Selective inhibitors of ATP-sensitive potassium channels (50 µM glibenclamide) and large conductance, Ca²⁺-activated potassium channels (50 nM iberiotoxin) were applied in vitro to soleus muscles fibers to evaluate the contribution of these channels to the resting potassium conductance of sarcolemma. Statistical analysis performed with paired Student’s t test indicates significant change (P<0.05) versus CTRL (a) or glibenclamide (b).