Sensitivity of native KATP channels to adenine nucleotides
Adenine nucleotide | Configuration | IC50 (μmol/l) | h | n |
---|---|---|---|---|
ATPγS | Open-cell | 8.2 ± 0.6 (NS) | 1.2 ± 0.1 | 5 |
Inside-out | 5.1 ± 1.0 | 0.9 ± 0.1 | 5 | |
ATP + 100 μmol/l ADP | Open-cell | 149 ± 57 (NS) | 1.4 ± 0.1 | 5 |
Inside-out | 123 ± 38 | 1.6 ± 0.2 | 10 | |
ATP + 1 mmol/l PCr | Open-cell | 14 ± 3 | 1.2 ± 0.1 | 6 |
ATP + 100 μmol/l LY294002 | Open-cell | 137 ± 24* | 1.1 ± 0.1 | 5 |
Inside-out | 9.0 ± 1.4 | 1.5 ± 0.3 | 5 |
Data are means ± SE. Results from native β-cell KATP channels exposed to Mg2+-containing internal solution with the additions indicated.
* P < 0.005; NS, nonsignificant, compared with equivalent data in the inside-out patch configuration. h, Hill coefficient; n, number of patches; PCr, phosphocreatine.