Figure 14. Mitochondrial Ca²⁺ uptake reduces the rate and extent of Ca²⁺-dependent slow inactivation.

A, dialysis with InsP₃ and thapsigargin in weak buffer (control) activates I_CRAC but then the current inactivates slowly (•). The extent of inactivation is reduced if mitochondria are energised (○). B and C summarise aggregate data comparing the extent (B) and rate (C) of inactivation of I_CRAC in control cells, in those in which cocktail was added to the solution and in cells exposed to cocktail and ruthenium red, to inhibit mitochondrial Ca²⁺ uptake. ^*P < 0.01. t_1/2, time at which I_CRAC had inactivated by 50 %.