High-fat diet and secretory capacity of insulin in rats

• Autor(a) principal: Garcia de Oliveira DUARTE, Ana Cláudia
• Data de Publicação: 2023
• Outros Autores: Faria FONSECA, Débora, Frenedozo SOAVE, Camila, SENE-FIORESE, Marcela, DÂMASO, Ana Raimunda, CHEIK, Nadia Carla
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Revista de Nutrição
• Texto Completo: https://periodicos.puc-campinas.edu.br/nutricao/article/view/9769
• topic: diet; Islets of Langerhans; obesity; pancreas; dieta; Ilhotas de Langerhans; obesidade; pâncreas

ObjectivesThis study investigated the effects of continuous feeding of rats with a palatable high-fat diet on: body weightgain, adiposity, liver and muscle glycogen content, blood glucose and insulin levels, and pancreatic morphologyand insulin secretion by in vitro isolated pancreatic beta cells. MethodsMale Wistar rats (21 days old) were fed with a palatable high-fat diet or a chow diet during 15wk. Body weightand food intake were recorded daily whereas blood glucose and insulin were analyzed weekly. After they werekilled, pancreas, liver, gastrocnemius muscle and adipose tissues were removed and weighted. Morphologyanalysis of pancreatic tissue sections was performed using light microscopy. Serum insulin and the insulinsecreted by isolated pancreatic islets, incubated for 90min under different concentrations of glucose, wereanalyzed by radioimmunoassay. ResultsThe palatable high-fat diet increased adiposity, body weight gain and liver glycogen content when comparedwith the animals fed with a chow diet. Blood glucose and insulin levels did not differ between groups. Theinsulin secretion from isolated islets increased in the high-fat diet group only at physiological concentrationsof glucose (G= 8.3mM). The size of the pancreas of rats receiving the high-fat diet decreased, although thenumber of beta cells increased. In addition, the lumen of pancreatic vessels was narrower compared withcontrol islets. ConclusionThe obesity resulting from a high-fat diet did not alter the blood glucose and insulin levels of fasted rats.Despite the morphological alterations of the pancreas, normal blood glucose concentration in rats receivinga high-fat diet remained at physiological range due to a preserved secretory capacity of the pancreatic islets.