Figure 7. BTP-2, a selective and potent inhibitor of SOCE reduces contractile force in young but not in aged skeletal muscle. (A) Intact EDL muscle stimulated with low and high frequencies every minute at 37°C; in control (no drug) contractions are shown, followed by the progressive effect of 20 μM BTP-2. On average the decrease in force with 20 μM it was 19 ± 4%. (B) Same protocol as in panel A, but using young SOL muscles, representative of 3 experiments. In these 3 experiments force decreased by 31 ± 7% in 15 min in SOL muscles. (C) EDL muscles from aged Wt mice were equilibrated with 30 and 80 Hz under control condition and then were exposed to 20 μM BTP-2. (D) SOL muscles from aged WT mice tested with the same protocol as shown for aged EDL muscles in panel C. No statistical differences between control and BTP-2 were seen in aged EDL and SOL muscles.