Fig. 5.
pHi-dependence vs. pHe-dependence of membrane conductance (Gm) in mSlc4a11-expressing oocytes. A: representative pHi and voltage traces recorded from an mSlc4a11-expressing oocyte during exposure to pHe = 7.5 and pHe = 8.5 solution under voltage-clamp. When the extracellular solution was pH 8.5, Vm was initially held at 0 mV to promote a mSlc4a11-mediated rise in pHi to ∼7.5, at which point Vm was clamped to the predicted value of EH (0 mV) to stabilize pHi at ∼7.5. When the extracellular solution was pH 7.5, Vm was held at −58 mV to maintain pHi at ∼7.5. Point 0 and Groups I–III denote regions of the trace where I–V relationships were measured to allow calculation of Gm measurements. There was no significant change in pHi or Gm between the first and last measurement in Groups I, II, or III and thus we took the average of the three readings for each group to be a single replicate to be reported in B and C. B: average values (n = 7 for all) of pHi measured at each of the points (or group, in which case the three values in each group were averaged) noted in A, with letters to indicate groups that are statistically indistinguishable (general linear model, confidence interval 95%). C: average values (n = 7 for all) of Gm measured at each of the points noted in A, with letters to indicate groups that are statistically indistinguishable.