Fig. (12).

The PKA inhibitor H-89 does not prevent blockage of T-type Ca²⁺ current by PGE₁ in NG108-15 cells, but the Epac agonist 8-pCPT-2Me-cAMP mimics the PGE₁ effect on holding current and current-voltage curve. A: T-type Ca²⁺ currents at -25 and -15 mV in control, in 0.2 μM PGE₁ (applied for 3 min) and after 4 min wash. When PGE₁ was applied, the cell had been in bath with 10 mM CaCl₂ and 10 μM H-89 for 88 min. Temperature 26.5ºC. B and C: Effect of 300 μM 8-pCPT-2Me-cAMp on the holding current (B) and on the current-voltage curve (C). Asterisks in B indicate current-voltage curves shown in C. Temperature 22.8ºC. From [71] and Meves (unpublished).