Figure 6

Effects of GTP cyclohydrolase 1 (GCH1) overexpression on intracellular [Ca²⁺]_i after myocardial infarction (MI). (A) Basal Ca²⁺ concentrations in the absence of isoproterenol; (B) The amplitude of Ca²⁺ transients elicited by electrical stimulation in the absence of isoproterenol; (C) Time to 50% decay (T50 decay) of Ca²⁺ transients in the absence of isoproterenol. (D) Original recordings of Ca²⁺ transients stimulated by electricity in the presence of isoproterenol in cardiomyocytes isolated from transgenic (Tg) and wild-type (WT) mice 4 weeks after MI or sham surgery. The vertical scale bar indicates 0.2 Fura-2 ratio (340/380 nM) unit, and the horizontal scale bar indicates 100 ms; (E) Basal [Ca²⁺]_i in the presence of isoproterenol; (F) Ca²⁺ transient amplitude in the presence of isoproterenol; (G) T50 decay of Ca²⁺ transients in the presence of isoproterenol; (H) Figure legend. *P < 0.05 versus sham WT groups; ^†P < 0.05 versus MI WT groups (n = 63–66 cells/goup).