Figure 1.

Overexpression of mIGF-1 results in increased muscle mass in SMA mice. (A) IGF-1 and (B) IGFR1 mRNA expression levels were determined by qRT–PCR in quadriceps muscles from P10 mIGF-1^NEG and mIGF-1^POS SMA and heterozygous (Het) littermate mice [*P < 0.05, **P < 0.01 and ***P < 0.001, n = 6 mice per group except for SMA mIGF-1^NEG (n = 7)]. (C) H&E stained cross-sections of quadriceps muscle from P10 SMA mIGF-1^NEG (left) and a P10 mIGF-1^POS SMA mice (right). Scale bar = 50 µm. (D) Weights of gastrocnemius (gastroc), quadriceps (quad) and triceps muscles in P10 mIGF-1^NEG and mIGF-1^POS SMA mice (*P < 0.05, n = 7 mIGF-1^NEG and n = 8 mIGF-1 + SMA mice). (E) Myofiber diameter in the P10 quadriceps muscle in SMA mIGF-1^NEG and SMA mIGF-1^POS mice (*P < 0.05, n = 3 mIGF-1^NEG, and n = 4 mIGF-1^POS SMA mice). Values represent average ± SEM.