Fig. 4.

Long-term effect of Sp-8CPT-2′-OMe-cAMP and 8CPT-2′-OMe-Ado on expression of bTREK-1 current. AZF cells were cultured for 48 h in media containing no further addition (control), Sp-8CPT-2′-OMe-cAMP (100 μM) (A), or 8CPT-2′-OMe-Ado (30 μM) (B). Whole-cell K⁺ currents were recorded from AZF cells in response to voltage steps to +20 mV applied from −80 mV at 30-s intervals with or without depolarizing prepulses to −20 mV. Pipettes contained standard solution (see Materials and Methods). A and B, representative K⁺ current traces recorded with (right traces) and without (left traces) depolarizing prepulses, and corresponding plot of bTREK-1 amplitudes with (○) and without (●) depolarizing pulses. Times indicated on traces correspond to those plotted on the graph at right. C, summary of experiments as in A and B: bars represent bTREK-1 current density expressed as mean ± S.E.M. of indicated number of determinations after 48 or 72 h of exposure to Sp-8CPT-2′-OMe-cAMP (100 μM) or 8CPT-2′-OMe-Ado (30 μM) as indicated.