Relative potency estimates (IC50 values) for inhibition of KATP channels by glibenclamide and HMR 1883 in cardiac tissues (guinea pigs), pancreatic β-cell (rat, RINm5F) and coronary vascular system (guinea pig) under hypoxic conditions
| IC50values for HMR 1883 | IC50 values for glibenclamide | ||
|---|---|---|---|
| μmol/liter | |||
| Cardiac tissue | Right papillary muscle | ||
| 2.4 μmol/l rilmakalim | 1.8 | 0.33 | |
| pHo = 7.4 | |||
| Cardiac tissue | Right papillary muscle | ||
| 7.3 μmol/l rilmakalim | 0.6 | 0.14 | |
| pHo = 6.0 | |||
| Cardiac tissue | Single ventricular | ||
| myocytes | 3 | 0.052 | |
| action potentials | |||
| 0.25 μmol/l | |||
| rilmakalim | |||
| pHo = 7.4 | |||
| Cardiac tissue | Single ventricular | ||
| myocytes | 0.4 | 0.01 | |
| action potentials | |||
| 0.25 μmol/liter | |||
| rilmakalim | |||
| pHo = 6.5 | |||
| Cardiac tissue | Single ventricular | ||
| myocytes | 0.8 | 0.02 | |
| whole-cell currents | |||
| 1 μmol/liter rilmakalim | |||
| pHo = 7.4 | |||
| Pancreatic β-cell | RINm5F cells | >10 | 0.009 |
| cell potentials | |||
| Coronary flow induced by hypoxia | Langendorff-perfused guinea pig heart (20% O2) | ≅100 | <1 |