title: Effects of exercise and muscle type on BDNF, NT-4/5, and TrKB expression in skeletal muscle.
abstract: Muscle-derived neurotrophins are thought to contribute to the adaptation of skeletal muscle to exercise, but the effects of brief exercise interventions on BDNF, NT-4/5, and trkB are not understood. RNA was extracted for RT-PCR from soleus and medial gastrocnemius of Sprague-Dawley rats exercised on a treadmill at speeds up to 20 m/min at 5% incline for 5 or 10 days. BDNF expression was elevated in soleus following 5 days (184%, P < 0.001) but not 10 days of exercise. NT-4/5 and trkB were not affected at either time-point. BDNF mRNA was significantly higher in soleus at rest when compared with medial gastrocnemius (193%, P < 0.05). No significant effects of muscle type were detected for NT-4/5 and trkB. Our results indicate differential control of BDNF expression between soleus and medial gastrocnemius following 5 days of exercise. BDNF may be a protein with an uncharacterized contribution to the acute adaptation of skeletal muscle to exercise, whereas NT-4/5 shows no response.
authors.affiliation: Health, Leisure and Human Performance Research Institute, and Spinal Cord Research Center, University of Manitoba, 404 Basic Medical Sciences, 730 William Avenue, Winnipeg, Manitoba R3E 3J7, Canada.
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Ogborn
authors.forename: Phillip F
authors.initials: PF
authors.lastname: Gardiner
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism*; D005260:Female; D018482:Muscle, Skeletal / Q000378:metabolism*; D009414:Nerve Growth Factors / Q000235:genetics / Q000378:metabolism*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020813:Receptor, trkB / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D012333:RNA, Messenger; D020813:Receptor, trkB; C073922:neurotrophin 4