Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/201555
Type: Artigo de periódico
Title: Reduced Insulin Clearance And Lower Insulin-degrading Enzyme Expression In The Liver Might Contribute To The Thrifty Phenotype Of Protein-restricted Mice.
Author: Rezende, Luiz F
Camargo, Rafael L
Branco, Renato C S
Cappelli, Ana P G
Boschero, Antonio C
Carneiro, Everardo M
Abstract: Nutrient restriction during the early stages of life usually leads to alterations in glucose homeostasis, mainly insulin secretion and sensitivity, increasing the risk of metabolic disorders in adulthood. Despite growing evidence regarding the importance of insulin clearance during glucose homeostasis in health and disease, no information exists about this process in malnourished animals. Thus, in the present study, we aimed to determine the effect of a nutrient-restricted diet on insulin clearance using a model in which 30-d-old C57BL/6 mice were exposed to a protein-restricted diet for 14 weeks. After this period, we evaluated many metabolic variables and extracted pancreatic islet, liver, gastrocnemius muscle (GCK) and white adipose tissue samples from the control (normal-protein diet) and restricted (low-protein diet, LP) mice. Insulin concentrations were determined using RIA and protein expression and phosphorylation by Western blot analysis. The LP mice exhibited lower body weight, glycaemia, and insulinaemia, increased glucose tolerance and altered insulin dynamics after the glucose challenge. The improved glucose tolerance could partially be explained by an increase in insulin sensitivity through the phosphorylation of the insulin receptor/protein kinase B and AMP-activated protein kinase/acetyl-CoA carboxylase in the liver, whereas the changes in insulin dynamics could be attributed to reduced insulin secretion coupled with reduced insulin clearance and lower insulin-degrading enzyme (IDE) expression in the liver and GCK. In summary, protein-restricted mice not only produce and secrete less insulin, but also remove and degrade less insulin. This phenomenon has the double benefit of sparing insulin while prolonging and potentiating its effects, probably due to the lower expression of IDE in the liver, possibly with long-term consequences.
Subject: Adipose Tissue, White
Animals
Diet, Protein-restricted
Down-regulation
Energy Intake
Energy Metabolism
Gene Expression Regulation, Enzymologic
Insulin
Insulin Resistance
Insulysin
Islets Of Langerhans
Liver
Mice
Mice, Inbred C57bl
Muscle, Skeletal
Phosphorylation
Protein Processing, Post-translational
Random Allocation
Receptor, Insulin
Signal Transduction
Weaning
Weight Gain
Rights: fechado
Identifier DOI: 10.1017/S0007114514001238
Address: http://www.ncbi.nlm.nih.gov/pubmed/25036874
Date Issue: 2014
Appears in Collections:Unicamp - Artigos e Outros Documentos

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