Mitochondrial modulation of insulin secretion: the role of protein malnutrition and physical training

Author(s)

Nayara de Carvalho Leite

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2016-11-09

Examining board members

Everardo Magalhães Carneiro; Carmen Veríssima Ferreira; Marcelo Alves Mori; Maria Fernanda Pereira de Araújo Demonte Forni; Eduardo Rebelato Lopes de Oliveira

• Advisor: Everardo Magalhães Carneiro

Abstract

The pancreatic cells secrete insulin according to the needs of the body. High insulin secretion is related to several diseases such as obesity, metabolic syndrome and hypoglycemic state. However, the secretion of insulin can be reduced in cases of increased peripheral sensitivity to the hormone, which is what happens in individuals who exercise regularly. Stimuli, including glucose, fatty acids and amino acids promotes exocytosis of insulin granules primarily via metabolism and production of metabolites that act as signaling molecules. Examples of these molecules are intermediates of the tricarboxylic acid cycle and reactive oxygen species. In this paper we show that both nutritional interventions and exercise alter insulin secretion by modulating mitochondrial and production of metabolic intermediates. Protein malnutrition followed by high supply of nutrients promotes increased insulin secretion, this is related to increased activity of the enzyme glutamate dehydrogenase and consequent increase in amplifying insulin secretion pathway. Moreover, physical training decreases insulin secretion, and this effect seems to be mediated by a non-canonical pathway triggered by interleukin 6 and consequent decreased production of ROS (AU)

• FAPESP's process: 13/00750-0 - MODULATION OF INSULIN SECRETION BY METABOLIC COUPLING FACTORS (MCFs) IN PANCREATIC ISLETS FROM UNDERNOURISHED OBESE MICE: A ROLE FOR CHRONIC EXERCISE.
• Grantee: Nayara de Carvalho Leite
• Support Opportunities: Scholarships in Brazil - Doctorate