Panel A shows representative current traces under isotonic, hypotonic, and DCPIB conditions. The traces include a scale of 500 picoamperes and 250 milliseconds, with 10 micromolar DCPIB indicated. Panel B shows a line graph of current density versus membrane voltage. The x-axis represents membrane voltage in millivolts, ranging from negative 120 to positive 120 millivolts, and the y-axis represents current density in picoamperes per picofarad. Data are shown for isotonic, hypotonic, and DCPIB conditions. Panel C shows a dose response curve of percentage inhibition versus DCPIB concentration in micromolar. The x-axis ranges from 0.01 to 100 micromolar, and the y-axis represents percentage inhibition. Data are shown at positive 100 millivolts and negative 100 millivolts. Panel D shows a line graph of relative current versus time in minutes during application of 10 micromolar DCPIB. Data are shown at positive 100 millivolts and negative 100 millivolts. Panel E shows a line graph of relative current versus time in minutes during application of 10 micromolar DCPIB. Panel F shows current density versus time during hypotonic conditions and application of 10 micromolar DCPIB. The x-axis represents time in minutes, and the y-axis represents current density in picoamperes per picofarad. Data are shown at positive 100 millivolts and negative 100 millivolts. Panel G shows representative current traces under hypotonic conditions and with 2 micromolar DCPIB. The scale bars indicate 250 picoamperes and 100 milliseconds. Panel H shows normalized current versus voltage under hypotonic conditions and with 2 micromolar DCPIB. The x-axis represents voltage in millivolts, and the y-axis represents current divided by maximum current. The inset illustrates the voltage clamp protocol, including positive 120 millivolts, negative 30 millivolts, negative 120 millivolts, and negative 80 millivolts, with a duration of 2000 milliseconds and a test pulse of 300 milliseconds.
Characteristics of DCPIB-dependent inhibition of 8C-8A(IL1 25 ) currents. (A) Representative whole-cell 8C-8A(IL125) current recorded from a cell dialyzed with normal pipette solution and cell swelling with hypotonic buffer (upper panel), after bath application of 10 μM DCPIB (bottom panel). The scale is the same for both traces. (B) I–V relationships of 8C-8A(IL125) from cells in isotonic, hypotonic, and hypotonic buffer with 10 μM DCPIB (n = 7). (C) CRCs of DCPIB inhibition at +100 mV and −100 mV (n = 6). (D and E) Time course of 10 μM DCPIB-induced inhibition (D, n = 5) and drug washout (E, n = 4). (F) Time course of 8C-8A(IL125) current evoked from cells dialyzed with normal pipette solution including 30 μM DCPIB and hypotonic cell swelling (n = 5). All cells were exposed to a hypotonic buffer for 9 min. After full activation, 10 μM DCPIB was applied until a new steady state was reached (5 min). (G) Representative tail currents of 8C-8A(IL125) recorded from a cell dialyzed with normal pipette solution and cell swelling with hypotonic buffer (upper panel), after bath application of 2 μM DCPIB (bottom panel). The scale is the same for both traces. (H) VDI of the tail currents in 8C-8A(IL125) (n = 6). Data are mean ± SEM. The voltage-clamp protocol used to elicit tail currents is shown in the inset.