Figure 4. Metabolic Analysis of RasGrf1−/− Mice. (A) Liver of RasGrf1−/− male animals (4-6 months old) contains a significant amount of glycogen after 24 hours of fasting contrasting with the complete absence in WT animals (4-6 months old). PAS staining was quantified using color deconvolution with ImageJ software (Broken Symmetry Software). Values represent relative staining of three different sections (*p=0.01 determined by a paired T-test). (B) Sirtuin mRNA expression in liver and heart of RasGrf1−/− male mice is significantly higher than in WT mice (*p=0.033; #p=0.035). Wild-type n = 4, RasGrf1−/− n = 3 (4-6 months old). (C) IGF-I plasma levels was measured in 3-5 months old male mice by RIA revealing a 30% reduction in RasGrf1−/−. Wild-type n = 10, RasGrf1−/− n = 9, *p<0.001.