Fig. 2

Block of astrocyte Kv channels by TEA and quinidine suppressed CPA-triggered Ca²⁺ influx. [Ca²⁺]i was measured using fura-2 as dye and quantified as fluorescence ratio. Astrocytes were bathed in Ca²⁺-free solution in the absence (a) or presence (b) of 20 mM TEA plus 30 μM quinidine; they were then exposed to 50 μM CPA followed by replenishment of 2 mM CaCl₂. Quantification of the Ca²⁺ release component (c) and the Ca²⁺ influx component (d) TEA + quinidine group was different from control group 56 s after Ca²⁺ replenishment (p < 0.05). With DMSO treatment, there was no Ca²⁺ release (e) but a small degree of Ca²⁺ influx upon Ca²⁺ replenishment (f). Results are mean ± SEM of 15–24 cells from five separate experiments