Light phase restricted fructose consumption and its implications on hypothalamic AMPK activation, melatonin production and glucose metabolism

Author(s)

Juliana de Almeida Faria

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas
• Defense date: 2016-07-29

Examining board members

Gabriel Forato Anhê; Andrea Maculano Esteves; Thomas Prates Ong; José Donato Júnior; Gabriela Freitas Pereira de Souza

• Advisor: Gabriel Forato Anhê

Abstract

A high fructose diet exerts a known modulation which is characterized by peripheral resistance to the insulin action, increased gluconeogenesis and hepatic steatosis on glucose metabolism. The exact mechanisms by which fructose triggers such actions are in continuous elucidation however it is known that the increased gluconeogenesis and the hyperphagia stimulation both result from activation of hypothalamic AMPK protein. Among several endocrine modulations, fructose promotes a reduction on nocturnal melatonin production. Melatonin, a hormone produced by pineal gland in a circadian manner, has the ability to synchronize the energetic metabolism by increasing insulin sensitivity and reducing gluconeogenesis. As melatonin production, it is known that hypothalamic AMPK activity has a circadian rhythm with increased values during the night phase. It has been shown recently that increased hypothalamic AMPK activity through pharmacologic activators is able to reduce nocturnal melatonin production. Interestingly, fructose consumption only during the light phase of the light / dark cycle results in metabolic changes similar to those described above, while fructose intake exclusively during the dark phase appears to exert milder metabolic effects. This study presents the results arising from the research of metabolic changes resulting from fructose intake at different phases of light / dark cycle; and in this context, we have assessed whether such changes are dependent on hypothalamic AMPK activity patterns and corticosterone production (AU)

• FAPESP's process: 12/11409-4 - Relationship between time of fructose intake and hypothalamic AMPK rhythm: possible connections of the metabolic outcome with melatonin production
• Grantee: Juliana de Almeida Faria
• Support Opportunities: Scholarships in Brazil - Doctorate