Fig. 4.

A: Masson's trichrome staining (blue stain) in the LV of control and Sirt1^endo−/− animals at different ages. Quantification of the fibrosis is presented in the bar graph as % of Masson's trichrome-positive area. No evidence of exaggerated fibrosis in Sirt1^endo−/− animals is seen. Masson's trichrome staining did not show any significant differences of LV fibrosis between Sirt1^endo−/− and control animals at different ages. B: cardiac expression of Collagen 1 measured by quantitative PCR in the LV of control and Sirt1^endo−/− animals at different ages. mRNA expression of collagen 1 in the LV of Sirt1^endo−/− and control animals was not different.