Lack of involvement of basic fibroblast growth factor (FGF-2) in capillary growth in skeletal muscles exposed to long-term contractile activity.

摘要: Fibroblast growth factors (FGFs) are involved in stimulation of angiogenesis tumors and other pathological circumstances. Increased activity normal skeletal muscles resulting from chronic electrical is a very potent stimulus for capillary but relationship between the initiation this involvement autocrine has yet to be established. Although FGF expression been reported stimulated 3 weeks, underway significantly earlier, beginning around days. The present experiments have therefore studied possible basic fibroblast factor (FGF-2) rat fast prior to, coincident with, growth. Muscle contractions were induced via electrodes implanted vicinity peroneal nerve maintained 8h/day 2, 4 or 7 Capillary/fiber ratio (C/F), based on staining endothelium alkaline phosphatase, was not changed either extensor digitorum longus (EDL) tibialis anterior (TA) after 2 days stimulation, increased TA both mRNA FGF-2, detected by ribonuclease protection assay, decreased all compared with control contralateral muscles; immunohistochemistry showed FGF-2 gene product nerves larger blood vessels capillaries. There no evidence up-regulation receptors flg bek FGF-2. presence arterioles may indicate role regulation flow since we previously shown it dilator small arterioles. However, lack correlation changes density protein its receptors, unlikely that directly linked muscles.