Figure 2. The extent of Cav1.3 VDF due to harmonin depends on the identity of the Cavβ subunit.
A and B, voltage protocol, representative IBa, and Fratio were as described in Fig. 1A and B except for channels containing the Cavβ2A subunit. n= 12 cells for Cav1.3(β2A) alone, n= 12 cells for +harmonin. C, comparison of facilitation obtained at +50 mV prepulse voltage (Fratio,+50) for β1b- or β2A-containing channels. *P < 0.001 compared to Cav1.3 alone, by t test. Number of cells is indicated in parentheses. D, percentage increase in Fratio,+50 due to harmonin (%Fharmonin) for channels with β1b (n= 12 cells) or β2A (n= 12 cells). %Fharmonin was calculated as (Fratio,+50 for Cav1.3 alone/mean Fratio,+50 for +harmonin) × 100. *P < 0.05 by t test.