Table 3.

Relative macroscopic amiloride-sensitive currents with divalent cations at −100 mV

	IMg/INa	ICa/INa	ISr/INa	IBa/INa
αS589A	0.00  ±  0.00	−0.01  ±  0.01	−0.01  ±  0.00*	−0.01  ±  0.00
αS589C	0.00  ±  0.00*	0.00  ±  0.00	0.01  ±  0.00*	0.00  ±  0.00
αS589D	−0.01  ±  0.01	0.06  ±  0.01*	0.05  ±  0.01*	0.03  ±  0.00*
wt	−0.02  ±  0.00	−0.01  ±  0.02	−0.02  ±  0.00	−0.01  ±  0.00

Amiloride-sensitive currents carried by divalent cations relative to I_Na are shown. All data are from experiments carried out with oocytes that had been injected with a BAPTA solution before the experiment (see Methods) to chelate intracellular Ca²⁺. Data are from 4-11 oocytes from 3-4 different batches per condition. ∗, different from wt (P < 0.01). Negative current ratios indicate that at −100 mV an outward current was measured with the divalent cation. I_Na at −100 mV was 31.7 ± 20.0 μA for wt, 12.2 ± 17.7 μA for αS589A, 3.2 ± 1.7 μA for αS589C, and 5.9 ± 2.0 μA for the αS589D mutant.