Membrane potential recordings from IALVs from Ip3r1fl/fl and Ip3r1ismKO mice in response to pharmacological ANO1 inhibition. Membrane potential was recorded in pressurized and contracting IALVs from Ip3r1fl/fl and Ip3r1ismKO mice using sharp electrodes prior to and subsequent to exposure to 3 μΜ Ani9. (A) Representative membrane potential recordings (30 s) from IALVs isolated from Ip3r1fl/fl (black lines) and following 3 μΜ Ani9 (blue lines) and in Ip3r1ismKO (red lines) and following 3 μΜ Ani9 (brown lines). (B) Zoom of the 4-s window outlined by the dashed box in A. (C–K) Analysis summary of membrane potential and AP characteristics including (C) AP frequency, (D) diastolic depolarization rate mv/s, (E) time to reach threshold, (F) min Vm, (G) threshold Vm, (H) peak AP Vm,, (I) time over threshold, and (J) sharp upstroke τ value. n = 5 controls (comprised of two female Ip3r1fl/fl and three male WT) and n = 6 Ip3r1ismKO IALVs with mean and SEM shown.
