TABLE 2

Sensitivity of native KATP channels to adenine nucleotides

Adenine nucleotideConfigurationIC50 (μmol/l)hn
ATPγSOpen-cell8.2 ± 0.6 (NS)1.2 ± 0.15
Inside-out5.1 ± 1.00.9 ± 0.15
ATP + 100 μmol/l ADPOpen-cell149 ± 57 (NS)1.4 ± 0.15
Inside-out123 ± 381.6 ± 0.210
ATP + 1 mmol/l PCrOpen-cell14 ± 31.2 ± 0.16
ATP + 100 μmol/l LY294002Open-cell137 ± 24*1.1 ± 0.15
Inside-out9.0 ± 1.41.5 ± 0.35
  • 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.