title: Short-term exercise increases GDNF protein levels in the spinal cord of young and old rats.
abstract: Neurotrophic factors may play a role in exercise-induced neuroprotective effects, however it is not known if exercise mediates changes in glial cell line-derived neurotrophic factor (GDNF) protein levels in the spinal cord. The aim of the current study was to determine if 2 weeks of exercise alters GDNF protein content in the lumbar spinal cord of young and old rats. GDNF protein was quantified via an enzyme-linked immunosorbent assay and Western blot. Immunohistochemical analysis localized GDNF in choline acetyltransferase (ChAT)-positive motor neurons and cell body areas were measured. Involuntary running in the young animals appeared to elicit the greatest increase in GDNF protein content (sixfold increase), followed by swimming (threefold increase) and voluntary running (twofold increase); however there was no significant difference between the modalities of exercise. Low-intensity running of the old animals significantly increased GDNF protein content in the spinal cord. Both young and old exercised animals showed a doubling in ChAT-positive motor neuron cell body areas. These results suggest that GDNF protein content in the spinal cord is modulated by exercise.
authors.affiliation: Department of Biological Sciences, Western Michigan University, 1903 W. Michigan Avenue, Kalamazoo, MI 49008-5410, USA. monicajmccullough@gmail.com
authors.forename: M J
authors.initials: MJ
authors.lastname: McCullough
authors.forename: A M
authors.initials: AM
authors.lastname: Gyorkos
authors.forename: J M
authors.initials: JM
authors.lastname: Spitsbergen
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D001324:Autoantigens / Q000378:metabolism; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000502:physiology*; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000378:metabolism*; D008124:Locomotion; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D009046:Motor Neurons / Q000378:metabolism / Q000473:pathology; D009414:Nerve Growth Factors / Q000378:metabolism; D010805:Physical Conditioning, Animal / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000378:metabolism* / Q000473:pathology; D013119:Spinal Cord Injuries / Q000473:pathology* / Q000534:rehabilitation*; D013550:Swimming; D013997:Time Factors
chemical_list: D001324:Autoantigens; C072167:CAT development factor; D051100:Glial Cell Line-Derived Neurotrophic Factor; C097741:Golgin subfamily A member 2; D008565:Membrane Proteins; D009414:Nerve Growth Factors