Fig 2.

Summary of PMA actions on exocytosis in gonadotropes. (A) Simultaneous time courses of [Ca²⁺]_i and C_m for a single control gonadotrope illustrating how the RRP size and the [Ca²⁺]_i threshold are determined by ramp [Ca²⁺]_i experiments. (B) Pretreatments with PMA (100 nM), 4α-PDD (1 μM), and BIS (500 nM) have no significant effect on the RRP size (defined in text as ΔC_m). (C) The calcium threshold (measured as [Ca²⁺]_Rmax/2) is lowered by PMA, but not by 4α-PDD or by PMA in combination with BIS.