title: Cholinergic nerve fibers in bone defects of a rat osteoporosis model and their regulation by implantation of bone substitution materials.
abstract: OBJECTIVE
  Bone is innervated by autonomic nervous system that consists of sympathetic and parasympathetic nerves that were recently identified in bone. Thus we asked whether parasympathetic nerves occur in bone defects and at the interface of substitution materials that were implanted for stabilization and improvement of healing in an osteoporosis animal model.
  
  
  METHODS
  Osteoporosis was induced in rats by ovariectomy and deficiency diet. A wedge-shaped osteotomy was performed in the metaphyseal area of femur. Eight different implants were inserted that were based on calcium phosphate cement, iron, silica-mineralized collagen, and modifications with strontium. Nerves were identified by immunohistochemistry with antibodies against vesicular acetylcholine transporter (VAChT), tyrosine hydroxylase (TH) and protein gene product 9.5 (PGP 9.5) as neuronal marker.
  
  
  RESULTS
  Cholinergic nerves identified with VAChT immunostaining were detected in defects filled with granulation tissue and in surrounding mast cells. No immunolabeling of cholinergic nerves was found after implantation. The general presence of nerves was reduced after implantation as shown by PGP 9.5. Sympathetic nerves identified by TH immunolabeling were increased in strontium functionalized materials.
  
  
  CONCLUSIONS
  Since cholinergic innervation was diminished after implantation a further increase in the compatibility of substitution materials to nerves could improve defect healing especially in osteoporotic bone.
authors.affiliation: Laboratory for Experimental Trauma Surgery, Justus-Liebig University Giessen, Kerkraderstr. 9, 35394 Giessen, Germany.
authors.forename: K S
authors.initials: KS
authors.lastname: Lips
authors.forename: V
authors.initials: V
authors.lastname: Kauschke
authors.forename: S
authors.initials: S
authors.lastname: Hartmann
authors.forename: U
authors.initials: U
authors.lastname: Thormann
authors.forename: S
authors.initials: S
authors.lastname: Ray
authors.forename: M
authors.initials: M
authors.lastname: Schumacher
authors.forename: M
authors.initials: M
authors.lastname: Gelinsky
authors.forename: S
authors.initials: S
authors.lastname: Heinemann
authors.forename: T
authors.initials: T
authors.lastname: Hanke
authors.forename: A R
authors.initials: AR
authors.lastname: Kautz
authors.forename: M
authors.initials: M
authors.lastname: Schnabelrauch
authors.forename: G
authors.initials: G
authors.lastname: Szalay
authors.forename: C
authors.initials: C
authors.lastname: Heiss
authors.forename: R
authors.initials: R
authors.lastname: Schnettler
authors.forename: V
authors.initials: V
authors.lastname: Alt
authors.forename: O
authors.initials: O
authors.lastname: Kilian
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000009:adverse effects*; D001842:Bone and Bones / Q000294:innervation*; D002799:Cholinergic Fibers / Q000187:drug effects*; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015663:Osteoporosis, Postmenopausal; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D018786:Bone Substitutes