title: Vitamin D₃ improves respiratory adjustment to fatigue and H-reflex responses in paraplegic adult rats.
abstract: We previously demonstrated that vitamin D₂ (ergocalciferol) triggers axon regeneration in a rat model of peripheral nerve transection. In order to confirm the regenerative potential of this neuroactive steroid, we performed a study in which vitamin D₃ (cholecalciferol) was delivered at various doses to paralytic rats. After spinal cord compression at the T10 level, rats were given orally either vehicle or vitamin D₃ at the dose of 50 IU/kg/day or 200 IU/kg/day. Three months later, M and H-waves were recorded from rat Tibialis anterior muscle in order to quantify the maximal H-reflex (H(max)) amplitude. We also monitored the ventilatory frequency during an electrically induced muscle fatigue known to elicit the muscle metaboreflex and an increase in respiratory rate. Spinal cords were then collected, fixed and immunostained with an anti-neurofilament antibody. We show here that vitamin D-treated animals display an increased number of axons within the lesion site. In addition, rats supplemented with vitamin D₃ at the dose of 200 IU/kg/day exhibit (i) an improved breathing when hindlimb was electrically stimulated; (ii) an H-reflex depression similar to control animals and (iii) an increased number of axons within the lesion and in the distal area. Our data confirm that vitamin D is a potent molecule that can be used for improving neuromuscular adaptive mechanisms and H-reflex responses.
authors.affiliation: Institut des Sciences du Mouvement, Etienne-Jules MAREY, UMR CNRS 6233, Université de la Méditerranée (Aix-Marseille II,Aix-Marseille Université), Parc Scientifique et Technologique de Luminy, Faculté des Sciences du Sport de Marseille, 13288 Marseille Cedex 09, France.
authors.forename: J
authors.initials: J
authors.lastname: Bianco
authors.forename: Y
authors.initials: Y
authors.lastname: Gueye
authors.forename: T
authors.initials: T
authors.lastname: Marqueste
authors.forename: O
authors.initials: O
authors.lastname: Alluin
authors.forename: J-J
authors.initials: JJ
authors.lastname: Risso
authors.forename: S
authors.initials: S
authors.lastname: Garcia
authors.forename: M-N
authors.initials: MN
authors.lastname: Lavault
authors.forename: M
authors.initials: M
authors.lastname: Khrestchatisky
authors.forename: F
authors.initials: F
authors.lastname: Feron
authors.forename: P
authors.initials: P
authors.lastname: Decherchi
mesh_terms: D000818:Animals; D002762:Cholecalciferol / Q000494:pharmacology*; D004195:Disease Models, Animal; D004576:Electromyography; D005260:Female; D006181:H-Reflex / Q000187:drug effects* / Q000502:physiology; D007150:Immunohistochemistry; D018763:Muscle Fatigue / Q000187:drug effects / Q000502:physiology; D009416:Nerve Regeneration / Q000187:drug effects; D010264:Paraplegia / Q000378:metabolism / Q000473:pathology*; D012123:Pulmonary Ventilation / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D014815:Vitamins / Q000494:pharmacology*
chemical_list: D014815:Vitamins; D002762:Cholecalciferol