Figure 4.

Expanded tracings of [Ca²⁺]_i in CMs before and after histone addition. Expanded intracellular calcium tracings (from Fig. 3) in electrically paced CMs (0.5 mHz) before (A) and after (B) addition of the histone mixture (5 μg/ml). In the lower panel, there was expanding width of intracellular calcium tracings, indicating defective [Ca²⁺]_i clearance during diastole. Tracings are representative of patterns in which n ≥ 4 each.