Effects of OM on cell-SPOC properties in neonatal cardiomyocytes. (A, left) Bar graph showing the values of the amplitude of SL oscillations and Z-disc oscillations in the absence and presence of OM. *, P < 0.05. (right) Relationship between SL amplitude versus Z-disc amplitude. Dashed line, –OM; solid line, +OM. A significant linear relationship was observed in the absence (Y = 1.826X – 0.168; R = 0.726; P < 0.0001) and presence (Y = 3.827X – 0.944; R = 0.663; P < 0.0001) of OM. (B, left) Relationship of cell-SPOC frequency versus shortening time. Open and closed circles indicate data in the absence (same as in Fig. S9 A) and presence of OM (taken from eight myocytes). Data were fitted by a curve Y = 0.853X⁻¹ (R = 0.989) in the presence of OM (compare with Fig. S9 A for the curve in the absence of OM). (right) Bar graphs showing mean values of shortening time or shortening velocity in the absence or presence of OM. *, P < 0.05. (C) Relationship of cell-SPOC frequency versus lengthening time. Open and closed circles indicate data in the absence (same as in Fig. S9 B) and presence of OM (taken from eight myocytes). Curve fitting was not performed because of the absence of a significant correlation. (right) Bar graphs showing mean values of lengthening time or lengthening velocity in the absence or presence of OM. *, P < 0.05. Error bars indicate means ± SEM.