The sympathetic nervous system regulates the three glycerol-3P generation pathways in white adipose tissue of fasted, diabetic and high-protein diet-fed rats
| Autor: | Luiz Carlos Carvalho Navegantes, Sílvia de Paula Gomes, Isis do Carmo Kettelhut, Rafael Rossi Valentim, Valéria Ernestânia Chaves, Renato Helios Migliorini, Maria Antonieta Rissato Garófalo, Maria Emilia Soares Martins Santos, Danúbia Frasson, Renata Polessi Boschini |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Blood Glucose
Male medicine.medical_specialty Sympathetic nervous system Sympathetic Nervous System Adipose Tissue White Glucose uptake medicine.medical_treatment Endocrinology Diabetes and Metabolism High-protein diet White adipose tissue Biology medicine.disease_cause Streptozocin Diabetes Mellitus Experimental Norepinephrine Endocrinology Glycerol Kinase Internal medicine Diabetes mellitus medicine Glyceroneogenesis Animals Insulin Rats Wistar Denervation Gluconeogenesis Fasting medicine.disease DIABETES MELLITUS (EXPERIMENTAÇÃO) Rats Glucose medicine.anatomical_structure Glycerophosphates Dietary Proteins |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| ISSN: | 0026-0495 |
| DOI: | 10.1016/j.metabol.2012.03.014 |
| Popis: | The aim of the present study was to investigate the participation of the sympathetic nervous system (SNS) in the control of glycerol-3-P (G3P) generating pathways in white adipose tissue (WAT) of rats in three situations in which the plasma insulin levels are low. WAT from 48 h fasted animals, 3 day-streptozotocin diabetic animals and high-protein, carbohydrate-free (HP) diet-fed rats was surgical denervated and the G3P generation pathways were evaluated. Food deprivation, diabetes and the HP diet provoke a marked decrease in the rate of glucose uptake and glycerokinase (GyK) activity, but a significant increase in the glyceroneogenesis, estimated by the phosphoenolpyruvate carboxykinase (PEPCK) activity and the incorporation of 1-[(14)C]-pyruvate into glycerol-TAG. The denervation provokes a reduction (~70%) in the NE content of WAT in fasted, diabetic and HP diet-fed rats. The denervation induced an increase in WAT glucose uptake of fed, fasted, diabetic and HP diet-fed rats (40%, 60%, 3.2 fold and 35%, respectively). TAG-glycerol synthesis from pyruvate was reduced by denervation in adipocytes of fed (58%) and fasted (36%), saline-treated (58%) and diabetic (23%), and HP diet-fed rats (11%). In these same groups the denervation reduced the PEPCK mRNA expression (75%-95%) and the PEPCK activity (35%-60%). The denervation caused a ~35% decrease in GyK activity of control rats and a further ~35% reduction in the already low enzyme activity of fasted, diabetic and HP diet-fed rats. These data suggest that the SNS plays an important role in modulating G3P generating pathways in WAT, in situations where insulin levels are low. |
| Databáze: | OpenAIRE |
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