Fig. 5.
Phosphatidylinositol 4,5-bisphosphate diC8 [PI(4,5)P2-diC8] increases Cl− current in detrusor smooth muscle cells. A: whole cell current density (I)-membrane potential (Vm) relationships obtained using voltage step protocol for control and PI(4,5)P2-diC8 applied intracellularly via the patch pipette. Closed and open circles indicate the current densities obtained in the absence (n = 59 cells, N = 19 guinea pigs) or presence (n = 57, N = 15) of 10 µM PI(4,5)P2-diC8, respectively. *Membrane potentials at which two groups are significantly different (P < 0.001, unpaired Student’s t test). B: voltage dependence of a ratio of the average current obtained in the presence of PI(4,5)P2-diC8 (IPI(4,5)P2-diC8) to the average current recorded under control conditions (IControl). C: distributions of current densities measured at the end of 100-ms voltage step from −100 to +130 mV. Circles represent the control group of current densities, and squares depict current densities obtained in the presence of PI(4,5)P2-diC8 in the pipette solution. Mean ± SE values for each group are shown as horizontal lines. *Statistically significant difference (P < 0.001, unpaired Student’s t test).