Glutamate modulation of melatonin synthesis in the rat pineal gland.

Author(s)

Darine Christina Maia Villela

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2008-04-03

Examining board members

Solange Castro Afeche; Ana Carolina Franco Ferreira; Cristoforo Scavone

• Advisor: Solange Castro Afeche

Abstract

The aim of this work was to study the effects of glutamate on melatonin synthesis, investigating the glutamate receptors involved and a possible interaction between the two predominant cell types of the pineal gland, pinealocytes and astrocytes; moreover, it was investigated the involvement of the transcription factor NF-<font face=\"symbol\">kB on the glutamate effects. To accomplish this, pineal glands were kept in culture and stimulated with glutamate or glutamate agonists. Isolated pinealocytes or in association with astrocytes in culture were also stimulated with glutamate. Melatonin was quantified by HPLC with electrochemical detection. Glutamate receptors were characterized by RT-PCR and NF-<font face=\"symbol\">kB activation was evaluated by gel shift assay. The data showed that glutamate has an inhibitory effect on melatonin synthesis that is mediated by groups I and II glutamate metabotropic receptors and AMPA receptor and that this effect involves the activation of astrocytic NF-<font face=\"symbol\">kB. (AU)