Ionic conditions are indicated in the left column. Statistical differences were evaluated using one way ANOVA with p<0.5. z values were statistical different when [Cl-] decreased from 140 or 70 to 25 mM but not when decreased from 140 to 70 mM. Also z values were different when the pH was varied between 5.5, 7.3 and 9. V0.5 values were not different when [Cl-] was decreased from 140 or 70 to 25 mM but were different by decreasing [Cl-] from 140 to 70 mM. No statistical differences were found in V0.5 when pH was decreased to 5.5 or increased to 9. In contrast V0.5 values were different when compared pH 9 and 5.5. Values given are mean±SDM.