Figure 1

Mitochondrial metabolism is impaired in skeletal muscles of NOS1-/- mice. Fibres were isolated from different muscles of wild-type and NOS1-/- mice at P120. (A) Mitochondrial membrane potential measured in fibres isolated from flexor digitorum brevis muscles, loaded with TMRM and treated with 5 μM oligomycin (Olm) or 4 μM FCCP. TMRM staining was monitored in six to ten fibres obtained from at least three different animals per experimental group. Data are expressed by setting the initial value as 1. (B) ATP production on mitochondria isolated from tibialis anterior and diaphragm muscles, at 10 minutes after substrate addition. Data are expressed by setting the initial value as 1. (C-D) Oxygen consumption on fibres isolated from tibialis anterior and diaphragm muscles, supplied with specific CI, CII and CIV mitochondrial complex substrates, as indicated in the Methods. (E) Quantitative analysis of the mtDNA copy number. Data are expressed by normalizing mtDNA values versus nuclear DNA. Each histogram represents the data obtained from at least five different animals per experimental group. * P <0.05 and ** P <0.01 versus the respective wild-type control.