Figure 1

Proliferation of primary skeletal myoblasts. (a) A quantitative analysis of myoblast proliferation using various concentrations of sildenafil for 24 or 72 h. The number of myoblasts was normalized to the corresponding number of myoblasts in the DMSO control and is presented as histograms (fold-increase). The number of myoblasts at each concentration was compared with the corresponding DMSO control using t-tests (*, significant, P<0.05) and a Bonferroni correction was conducted. The results are presented as the means±s.e. A quantitative analysis of myoblast proliferation using various concentrations of sildenafil for various time periods is presented in Supplementary Figure 1a. The number of places used in the analysis of the sildenafil effect on myoblast proliferation is presented in Supplementary Figure 1b. (b) Representative images of myoblasts treated with DMSO or 50 nM sildenafil for 84 h are presented. The scale bar indicates 50 μm. The proliferation of primary skeletal myoblasts is significantly enhanced by 50 nM sildenafil treatment for 24 h or longer periods.