title: Oxytocin promotes bone formation during the alveolar healing process in old acyclic female rats.
abstract: OBJECTIVE
  OT was reported to be a direct regulator of bone mass in young rodents, and this anabolic effect on bone is a peripheral action of OT. The goal of this study was to investigate the peripheral action of oxytocin (OT) in the alveolar healing process in old female rats.
  
  
  METHODS
  Females Wistar rats (24-month-old) in permanent diestrus phase, received two ip (12h apart) injections of saline (NaCl 0.15M - control group) or OT (45μg/rat - treated group). Seven days later, the right maxillary incisor was extracted and analyses were performed up to 28 days of the alveolar healing process (35 days after saline or OT administration).
  
  
  RESULTS
  Calcium and phosphorus plasma concentrations did not differ between the groups. The plasma biochemical bone formations markers, alkaline phosphatase (ALP) and osteocalcin were significantly higher in the treated group. Histomorphometric analyses confirmed bone formation as the treated group presented the highest mean value of post-extraction bone formation. Tartrate-resistant acid phosphatase (TRAP) was significantly reduced in the treated group indicating an anti-resorptive effect of OT. Immunohistochemistry reactions performed in order to identify the presence of osteocalcin and TRAP in the bone cells of the dental socket confirmed these outcomes.
  
  
  CONCLUSIONS
  OT was found to promote bone formation and to inhibit bone resorption in old acyclic female rats during the alveolar healing process.
authors.affiliation: Multicentric Graduate Studies Program in Physiological Sciences, Univ. Estadual Paulista, Araçatuba, São Paulo, Brazil. vilma@foa.unesp.br
authors.forename: Vilma Clemi
authors.initials: VC
authors.lastname: Colli
authors.forename: Roberta
authors.initials: R
authors.lastname: Okamoto
authors.forename: Poli Mara
authors.initials: PM
authors.lastname: Spritzer
authors.forename: Rita Cássia Menegati
authors.initials: RC
authors.lastname: Dornelles
mesh_terms: D000135:Acid Phosphatase / Q000032:analysis / Q000097:blood; D000367:Age Factors; D000469:Alkaline Phosphatase / Q000097:blood; D000539:Alveolar Process / Q000187:drug effects* / Q000473:pathology; D000818:Animals; D015415:Biomarkers / Q000097:blood; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D001857:Bone Matrix / Q000187:drug effects / Q000473:pathology; D001862:Bone Resorption / Q000473:pathology / Q000517:prevention & control; D002118:Calcium / Q000097:blood; D004031:Diestrus; D005260:Female; D007180:Incisor / Q000601:surgery; D007527:Isoenzymes / Q000032:analysis / Q000097:blood; D008437:Maxilla / Q000473:pathology; D010006:Osteoblasts / Q000187:drug effects / Q000473:pathology; D015675:Osteocalcin / Q000032:analysis / Q000097:blood; D010011:Osteocytes / Q000187:drug effects / Q000473:pathology; D010012:Osteogenesis / Q000187:drug effects*; D010121:Oxytocin / Q000494:pharmacology*; D010758:Phosphorus / Q000097:blood; D051381:Rats; D017208:Rats, Wistar; D000071681:Tartrate-Resistant Acid Phosphatase; D013997:Time Factors; D014081:Tooth Extraction; D020390:Tooth Socket / Q000187:drug effects* / Q000473:pathology; D014945:Wound Healing / Q000187:drug effects
chemical_list: D015415:Biomarkers; D050071:Bone Density Conservation Agents; D007527:Isoenzymes; D015675:Osteocalcin; D010758:Phosphorus; D010121:Oxytocin; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D002118:Calcium