Fig. 6.

Effect of long-term absence of estrogen on Ca²⁺ spark amplitude (A) and mass (C). Spark amplitudes were larger in the ovariectomized (OVx) group than in the sham-operated (Sham) and OVx + 17β-estradiol replaced (OVx + E) group in the absence (A) and presence (B) of isoprenaline (ISO). OVx myocytes had larger spark masses compared with Sham and OVx + E myocytes in the absence (C) and presence (D) of ISO. Sham: n = 55/5, OVx: n = 36/3, and OVx + E: n = 40/4. *P < 0.05; **P < 0.01; ***P < 0.001.