Alveolar bone repair of aged rats treated with estradiol and raloxifene

• Grant number: 08/04565-4
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2008
• End date: August 31, 2010
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal Investigator: Rita Cássia Menegati Dornelles
• Grantee: Rita Cássia Menegati Dornelles
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

The estrogen deficiency is an important pathogenic factor in bone loss associated with menopause, considering that hormonal replacement treatment results in an increase in bone mineral density. Studies carried out in our laboratory showed an evident delay in the alveolar wound healing process in young ovariectomized rats as well as in ovary-intact aged rats (20-24m). Probably the E2 deficiency creates conditions which favor osteoclastogenesis and reduction of apoptosis of the osteoclasts.The aim of this study is to evaluate the alveolar bone regeneration process and to analyze the concentration of cellular activity markers in bone metabolism in young and ovariectomized (OVX) or not-aged rats treated or not with hormonal therapy. In this study, we use aged Wistar rats, 18 months old that had been ovariectomized 1 year before; and young rats (4 m) with regular estrous cycle. During 60 days, OVX rats will receive hormonal treatment according to the following groups: 1) OVX/OM will be given pellets with maize corn oil; 2) OVX/E2 will be given pellets with estrogen (400 ug of 17b-estradiol); 3) OVX/RLX will be given, by gavage, raloxifene (1mg/Kg/day). The maxillary right central incisors will be extracted after 32 days of treatment for futher anaslysis of the alveolar bone regeneration.Twenty-eight days after the extraction, blood will be collected, in order to obtain serum and plasma. And after that, the rats will the be euthanized so that the jaws are extracted. The collected material will be prepared for confection of slides and further hystomorphommetric analysis. Serum and plasma will be stored for the determination of bone markers. (AU)