Mean ± SEM for parameters used to fit ADP concentration-response relationships for the indicated KATP channels in the presence or absence of sulfonylureas
| Channel | Parameter | Mg2+ | No sulfonylurea | +Sulfonylurea |
| 30 µM gliclazide | ||||
| Kir6.2/SUR1 | IC50 (µM) | − | 62 ± 3 (n = 6) | 59 ± 7 (n = 6) |
| Kir6.2/SUR1 | IC50 (µM) | + | 258 ± 57 (n = 12) | 64 ± 3a (n = 6) |
| Kir6.2/SUR1 | EC50 (µM) | + | 13 ± 2 (n = 12) | n.a. |
| Kir6.2/SUR1 | a | + | 3.2 ± 0.7 (n = 12) | n.a. |
| Kir.2/SUR2A-YS | IC50 (µM) | − | 95 ± 5 (n = 6) | 88 ± 11 (n = 6) |
| Kir.2/SUR2A-YS | IC50 (µM) | + | 310 ± 56 (n = 6) | 286 ± 39 (n = 6) |
| Kir.2/SUR2A-YS | EC50 (µM) | + | 16 ± 5 (n = 6) | 19 ± 3 (n = 6) |
| Kir.2/SUR2A-YS | a | + | 1.2 ± 0.3 (n = 6) | 1.1 ± 0.1 (n = 6) |
| 1 µM glibenclamide | ||||
| Kir6.2/SUR2A | IC50 (µM) | − | 96 ± 19 (n = 6) | 80 ± 8 (n = 6) |
| Kir6.2/SUR2A | IC50 (µM) | + | 280 ± 70 (n = 7) | 315 ± 49 (n = 7) |
| Kir6.2/SUR2A | EC50 (µM) | + | 22 ± 8 (n = 7) | 17 ± 2 (n = 7) |
| Kir6.2/SUR2A | a | + | 1.1 ± 0.3 (n = 7) | 1.1 ± 0.2 (n = 7) |
| Channel | Parameter | Mg2+ | No sulfonylurea | +Sulfonylurea |
| 30 µM gliclazide | ||||
| Kir6.2/SUR1 | IC50 (µM) | − | 62 ± 3 (n = 6) | 59 ± 7 (n = 6) |
| Kir6.2/SUR1 | IC50 (µM) | + | 258 ± 57 (n = 12) | 64 ± 3a (n = 6) |
| Kir6.2/SUR1 | EC50 (µM) | + | 13 ± 2 (n = 12) | n.a. |
| Kir6.2/SUR1 | a | + | 3.2 ± 0.7 (n = 12) | n.a. |
| Kir.2/SUR2A-YS | IC50 (µM) | − | 95 ± 5 (n = 6) | 88 ± 11 (n = 6) |
| Kir.2/SUR2A-YS | IC50 (µM) | + | 310 ± 56 (n = 6) | 286 ± 39 (n = 6) |
| Kir.2/SUR2A-YS | EC50 (µM) | + | 16 ± 5 (n = 6) | 19 ± 3 (n = 6) |
| Kir.2/SUR2A-YS | a | + | 1.2 ± 0.3 (n = 6) | 1.1 ± 0.1 (n = 6) |
| 1 µM glibenclamide | ||||
| Kir6.2/SUR2A | IC50 (µM) | − | 96 ± 19 (n = 6) | 80 ± 8 (n = 6) |
| Kir6.2/SUR2A | IC50 (µM) | + | 280 ± 70 (n = 7) | 315 ± 49 (n = 7) |
| Kir6.2/SUR2A | EC50 (µM) | + | 22 ± 8 (n = 7) | 17 ± 2 (n = 7) |
| Kir6.2/SUR2A | a | + | 1.1 ± 0.3 (n = 7) | 1.1 ± 0.2 (n = 7) |
Parameters were obtained from the data shown in Fig. 4, but all values are the mean of the fits to the individual dose–response curves. a is the maximal increase in KATP current caused by MgADP activation (Eq. 4; note the maximal amplitude of activation is given by 1 + a). n.a., not applicable.
P < 0.01 against control (Student’s t test).