Activity of RANK/RANKL/OPG system, evaluated by immunohistochemistry, in rats submitted to manipulation of the neonatal androgen environment

• Grant number: 14/12125-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2014
• End date: August 31, 2015
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal Investigator: João Cesar Bedran de Castro
• Grantee: Olívia Borghi Nascimento
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

The RANK / RANKL / OPG system has been proposed as a potential mediator of bone loss induced by sex steroid deficiency. It is known that the skeletal system is sexually dimorphic, and sex hormones are considered key mediators of skeletal sexual dimorphism. Several studies suggest that a deficiency of sex steroids at a critical time in bone maturation, can irreversibly inhibit the gain peak bone mass. As well known, sex steroids regulate the expression of OPG and RANKL, as orchiectomy in rats increases mRNA expression of RANKL and hormonal factors such as estradiol, act by decreasing the rate of expression of mRNA for OPG / RANKL, stimulates growth in the production of OPG and decreased of RANKL synthesis. Whereas there are few studies that evaluate the influence of sex hormones during the neonatal stage on the RANK / RANKL / OPG system throughout the development, the understanding of these mediators is fundamental to the understanding of the mechanisms that modulate skeletal homeostasis. Thus, aim of this study is to evaluate the effects of androgen manipulation during the neonatal period on the activity / RANKL / RANK system OPG, evaluated by immunohistochemical analysis in prepubertal, pubertal and adulthood animals subjected to castration or neonatal androgenization.