Table 2.

Reversal Potential (Erev) and Permeability Ratios (PX/PCl−) for CASTOR and castor-2

CASTORcastor-2
Ion (X)Erev (mV)PX/PCl−Erev (mV)PX/PCl−
K+36 ± 2 (n = 40)6.0a28 ± 2 (n = 48)3.7a
Na+11 ± 1 (n = 8)1.6a25 ± 3 (n = 13)3.2a
Ca2+−29 ± 2 (n = 13)0.5b−32 ± 2 (n = 19)0.6b
  • a Permeability ratios calculated from reversal potentials using equation Erev = RT/zF × ln(PK+[K]o/PNa+[Na]i).

  • b Permeability ratios calculated from reversal potentials using equation Erev= RT/F × ln(√((4PCa2+[Ca]o/PK+[K]i)+1/4) − 1/2), where RT/F = 25.26 mV and Z = 1. The junction potential correction was as follows: NaCl (250 mM/20 mM, agar bridge, 2 M KCl), Vm = Vcmd + 2.3 mV; KCl (250 mM/20 mM, agar bridge, 2 M KCl), Vm = Vcmd + 1.2 mV; CaCl2 (125 mM/10 mM, agar bridge, 2 M KCl), Vm = Vcmd + 3.1 mV.