Figure 3

Relative levels of basal Ca²⁺ in rat cardiomyocytes in control, hypoxic conditions and in hypoxic conditions in the presence of et-GSH, GSSG, tet-GSSG, GSNO and NAC. The measurements were carried out at 2 min for control normoxia and hypoxia, and at 5 min for all other exposures. Average ratio ([Ca²⁺]_i at relaxation/[Ca²⁺]_i at peak) × 100% is presented for each condition. For all Ca²⁺ transients [Ca²⁺]_i at relaxation is determined at time point after Ca²⁺ peak in control normoxic cardiomyocytes when fluorescent signal reaches 20% of the peak value (on average at 250 msec). n = 11–17. Mean value ± S.D. Statistical analysis was performed using one-way ANOVA (F = 115.0, p < 0.00001) with post hoc testing (using paired samples Student’s t-test with Bonferroni correction); after a Bonferroni correction, a p-value < 0.003 was considered as statistically significant; *p < 0.001 for all conditions vs hypoxia.