Evaluation of the effect of thyroid hormone on bone structure and physiology of mice with inactivation of Gene a2A-adrenoceptor.

Author(s)

Gisele Miyamura Martins

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2013-02-05

Examining board members

Cecilia Helena de Azevedo Gouveia Ferreira; Rodrigo Cardoso de Oliveira; Miriam Oliveira Ribeiro

• Advisor: Cecilia Helena de Azevedo Gouveia Ferreira

Abstract

One of the most important finds of the recent years is that bone remodeling is subject to the control of the CNS, with SNS acting as the peripheral effector. However, a recent study of our group showed that mice <font face=\"Symbol\">a2A/<font face=\"Symbol\">a2C-AR-/- have a high bone mass phenotype, even though are resistant to the thyroid hormone-induced osteopenia. In order to verify the role of <font face=\"Symbol\">a2A-AR-/- in these cases, we had as objectives to evaluate whether the isolated inactivation of <font face=\"Symbol\">a2A-AR interferes with the bone structure, and to evaluate the action of HT on these animals. We have observed that the longitudinal length of the bones of <font face=\"Symbol\">a2A-AR-/- animals are lower than those of wild type animals and the analysis of the femur by <font face=\"Symbol\">mCT showed a lower cortical porosity. With regard to treatment with thyroid hormone, we observed that <font face=\"Symbol\">a2A-AR-/- animals were resistant to the bone length decrease caused by thyroid hormone excess. We also noticed that the trabecular bone of <font face=\"Symbol\">a2A-AR-/- animals was more sensitive to the deleterious effects of thyrotoxicosis. Moreover, the cortical bone and bone biomechanical parameters KO animals were less sensitive. In conclusion, the findings of this study suggest that <font face=\"Symbol\">a2A-AR is involved in the process of bone growth and that this receptor may mediate at least partly, negative actions of T3 in this process as well as the HT in the cortical bone. (AU)

• FAPESP's process: 10/04911-0 - Evaluation of the effect of thyroid hormone on bone structure and physiology of mice with gene inactivation of the alpha 2A adrenoceptor
• Grantee: Gisele Miyamura Martins
• Support Opportunities: Scholarships in Brazil - Master