Figure 1: Measurements of total passive tension, before and after gelsolin treatment. (a) mouse left ventricle (MLV), (b) bovine left ventricle (BLV), (c) bovine left atrium (BLA) before gelsolin extraction (control, black) and after gelsolin treatment (white). Gelsolin treatment decreases passive tension. Inset of (b): example of titin gel (SDS agarose) with BLV and BLA samples. Inset of (c): tension at SL = 2.25  𝜇 m before and after gelsolin treatment with % tension reduction. MLV is more greatly affected by thin filament extraction than BLA, with BLV at an intermediate level. Error bars are SE (for clarity plotted only every 0.05  𝜇 m).