Table 1.

Properties of α,β-methylene-ATP concentration–effect curves with and without IVM on P2X4 receptors alone or when expressed in combination with P2X6 receptors

Receptorα,β-Methylene-ATPThreshold (μm)EC50m)Hill slopeImax(−nA)1-an
P2X4Control300>3001-b433  ± 1137
+IVM (3 μm)1019.8  ± 3.72.0  ± 0.21608  ± 3116
P2X4/P2X6Control1025.1  ± 2.7*1.8  ± 0.3360  ± 508
+IVM (3 μm)315.6  ± 1.4*2.2  ± 0.13739  ± 2449
  • F1-a Imax is the largest current on the concentration–effect curve to α,β-methylene-ATP (100 or 300 μm).

  • F1-b The Hill slope was not possible to determine.

  • *Statistical difference (at p < 0.05) between these two EC50 values (p = 0.005; unpaired Student’s t test; also see Figure 4 for graphs).