UCP3 protein expression is lower in type I, IIa and IIx muscle fiber types of endurance-trained compared to untrained subjects.

摘要: Uncoupling protein 3 (UCP3) is a muscle mitochondrial believed to uncouple the respiratory chain, producing heat and reducing aerobic ATP production. Our aim was quantify compare UCP3 levels in type I, IIa IIx skeletal fibers of endurance-trained (Tr) healthy untrained (UTr) individuals. content quantified using Western blot immunofluorescence. Skeletal fiber determined by both an enzymatic ATPase stain expression measured biopsies 46% lower (P=0.01) Tr compared UTr group. different expressed as follows; IIx>IIa>I for groups (P<0.0167) but all types when subjects (P<0.001). results show that training status did not change hierarchical types. However, it affected more I than fibers. We suggest this decrease may be relation relative improvement antioxidant defense systems might, consequence, participate induced mechanical efficiency.