Increased expression of fibroblast growth factors in a rabbit skeletal muscle model of exercise conditioning.

摘要: Increased tonic contractile activity from exercise or electrical stimulation induces a variety of changes in skeletal muscle, including vascular growth, myoblast proliferation, and fast to slow fiber type conversion. Little is known about the cellular control such changes, but pleiotropic biochemical modulators as fibroblast growth factors (FGFs) may be involved this response thus regulated stimuli. We examined regulation FGF expression an vivo model conditioning previously shown exhibit FGFs were extracted by heparin-affinity chromatography extensor digitorum longus muscles adult rabbits subjected chronic motor nerve at 10 Hz. Growth factor (expressed units [GFUs]) muscle stimulated for 3 21 d was assayed [3H]thymidine incorporation 3T3 fibroblasts compared with that present contralateral unstimulated muscle. A small increase heparin-binding mitogenic observed early stimulation, increased significantly when normalized either wet weight (stimulated, 287 +/- 61 GFU/g; unstimulated, 145 39 GFU/g) protein 5.3 1.1 GFU/mg; 2.2 0.6 GFU/mg) (+/- SE, P less than 0.05). Western analysis demonstrated amounts peptides immunological identity acidic basic The content study synchronous neovascularization, conversion model. These results demonstrate associated suggests these proteins play regulatory role occur during conditioning.