Fig. 4.

Viability assay of single adult cardiac myocytes. Experiment was done with 5 WT and 5 KO mice 2.5–5 mo old. A: microscopic fields containing single myocytes from WT and KO hearts previously treated in parallel with PBS or H₂O₂. Viable (unstained) vs. dead (blue) myocytes were counted, and each field was scored for the percentage of blue cells (death score). B: distribution analysis of all the fields scored (shown by n) according to their death score (0–100%). Clustering at the left of the x-axis indicates a low death index. C: average death score per treatment and genotype (n = 5 Mfn-1 WT or KO mice; *P < 0.05 WT vs. KO and #P < 0.05 PBS vs. H₂O₂). D: Western blot analysis performed to detect Mfn-1 protein levels in Mfn-1 WT and KO single myocytes following treatment with PBS and H₂O₂. GAPDH is used as a protein loading control. Numbers at left indicate respective molecular masses (37–250 kDa).