Role of melatonin in regulating circadian rhythms in peripheral tissues involved in energy metabolism: evaluation of the daily profile of the expression of clock genes.

Author(s)

Marco Taneda

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2011-07-28

Examining board members

Jose Cipolla Neto; Fernanda Gaspar do Amaral; Daniella do Carmo Buonfiglio; Rodrigo Antonio Peliciari Garcia; Silvana Auxiliadora Bordin da Silva

• Advisor: Jose Cipolla Neto

Abstract

The energy metabolism is dependent, between other factors, of a circadian timing among the tissues participants of the metabolic regulation. The synchronization process appears to depend on the expression of clock genes and mediators such as melatonin, involving the central oscillator and peripheral oscillators. We have investigated the role of melatonin in the expression of clock genes in peripheral tissues. Rats have been divided into two groups: pinealectomized and control rats. After 45 days the animals were sacrificed and their tissues of interest have been extracted for analysis by conventional PCR. Pinealectomy caused a significant disruption in the temporal expression of almost all genes of muscle tissue and fat tissue. The liver tissue was the least affected by changes of pinealectomy. In conclusion, these data show that melatonin is necessary for maintaining the rhythmicity of clock genes in skeletal muscle, adipose tissue and liver tissue. (AU)