TABLE 1

Effect of SEA (0.1 μM) on peak and steady-state outward currents mediated by NCX1.1 and mutant Na+-Ca2+ exchangers

Exchanger Type Ipeak (% Inhibition) n Iss (% Inhibition) n
1 μM Ca2+
   WT 57 ± 6 12 88 ± 5 10
   F223E 54 ± 4 12 100a 11
   K225Q 54 ± 8 7 73 ± 9 8
   Δ229-232 7 ± 3* 11 20 ± 5* 11
   K229Q 22 ± 4* 14 64 ± 6* 14
   Δ680-685 32 ± 8* 8 78 ± 3 8
10 μM Ca2+
   WT 31 ± 8 8 71 ± 7 8
   F223E 57 ± 6* 10 87 ± 3* 10
   K225Q 25 ± 4 7 71 ± 4 7
   Δ229-232 9 ± 3* 8 21 ± 10* 8
   K229Q 14 ± 5 13 36 ± 3* 13
   Δ680-685 31 ± 6 14 65 ± 5 14

  • Ipeak, peak outward current; Iss, steady-state outward current; WT, wild-type NCX1.1

  • ↵ a Block is to zero current level (see text for details)

  • ↵* P < 0.05 compared with wild type