ABSTRACT
Glycolysis is the core of intermediate metabolism, an ancient pathway discovered in the heydays of classic biochemistry. A hundred years later, it remains a matter of active research, clinical interest and is not devoid of controversy. This review examines topical aspects of glycolysis in the brain, a tissue characterized by an extreme dependence on glucose. The limits of glycolysis are reviewed in terms of flux control by glucose transporters, intercellular lactate shuttling and activity-dependent glycolysis in astrocytes and neurons. What is the site of glycogen mobilization and aerobic glycolysis in brain tissue? We scrutinize the pervasive notions that glycolysis is fast and that catalysis is channeled through supramolecular assemblies. In brain tissue, most glycolytic enzymes are catalytically silent. What then is their function?
Subject(s)
Astrocytes/metabolism , Brain/metabolism , Glycogen/metabolism , Glycolysis/physiology , Lactic Acid/metabolism , Neurons/metabolism , Animals , Astrocytes/chemistry , Brain Chemistry/physiology , Energy Metabolism/physiology , Glucose/analysis , Glucose/metabolism , Glycogen/analysis , Humans , Lactic Acid/analysis , Neurons/chemistry , Time FactorsABSTRACT
Objetivo: Relacionar los niveles séricos de adiponectina con el estado nutricional y resistencia a la insulina (RI) en adultos con o sin síndrome metabólico (SM), pertenecientes a la cohorte CDC de Canarias en Venezuela. Métodos: La muestra incluyó 62 adultos Canarios e hijos residentes en Venezuela. Se efectuó antropometría, determinación de presión arterial, análisis sérico de: glucosa, HDL-colesterol, triglicéridos, insulina y adiponectina. Resultados: La adiponectina fue significativamente inferior, comparado con los controles, en obesos, (2,16 ± 0,51 ng/ml vs. 2,62 ± 0,42 ng/ml, p =0,032) y sujetos con SM (1,85 ± 0,46 ng/ml vs. 2,55 ± 0,43 ng/ml, p =0,000). La adiponectina mostró una correlación inversa con edad, presión arterial diastólica así como con los indicadores de RI (HOMA, índice triglicéridos / HDL-colesterol y trigliceridemia). Conclusión: En la totalidad de la muestra, los sujetos mostraron hipoadiponectinemia, implicando alto riesgo cardiovascular, que podría explicarse parcialmente por la presencia de obesidad, SM, RI o relacionado con mayor edad que incrementa el riesgo de estrés oxidativo.
Objective: To relate serum adiponectin levels with nutritional status and insulin resistance (IR) in adults with and without metabolic syndrome (MS) cohort belonging to the CDC de Canarias en Venezuela. Methods: The sample included 62 people, Canaries and children living in Venezuela. Anthropometry, blood pressure determination, analysis of fasting serum glucose, HDL-cholesterol, triglycerides, insulin and adiponectin, were performed. Results: Serum levels of adiponectin were significantly lower in individuals with obesity (2.16 ± 0.51 vs 2.62 ± 0.42, p = 0.032) and subjects with MS (1.85 ± 0.46 vs 2.55 ± 0.43 p = 0.000), compared to respective control group. Pearson analysis showed an inverse correlation of adiponectin with age, diastolic blood pressure as well as indicators of insulin resistance (HOMA, index triglycerides, HDL-cholesterol and triglycerides). Conclusion: In the whole sample, the subjects showed low serum adiponectin, implying a high cardiovascular risk, which could be partially explained by the presence of obesity, MS, RI or related to older age that increases the risk of oxidative stress.
