Fig. 4

Differences in plasma levels of IGF1 and the expression of IGF1, STAT5A, and STAT5B in skeletal muscle between wild-type (WT) and STAT5B^−/− mice. Mean (± SEM) concentrations of a IGF1 in plasma and b Igf1 mRNA and c protein, d Stat5a mRNA and e protein, and f Stat5a mRNA and g protein in quadriceps muscles of male WT (black bars), male STAT5B^−/− (light grey bars), female WT (dark grey bars), and female STAT5B^−/− (white bars) mice at 6, 12, and 24 weeks of age (n = 8 per group). Values for each group are expressed relative to those in male WT mice at 6 weeks of age. Unlike letters within each graph denote significant differences (P < 0.05) between groups at each age only. Asterisks denote significant differences (*P < 0.05, ***P < 0.001) at each age only