RESUMO
Adipose tissue secretes a variety of bioactive substances that are associated with chronic inflammation, insulin resistance, and an increased risk of type 2 diabetes mellitus. While resistin was first known as an adipocyte-secreted hormone (adipokine) linked to obesity and insulin resistance in rodents, it is predominantly expressed and secreted by macrophages in humans. Epidemiological and genetic studies indicate that increased resistin levels are associated with the development of insulin resistance, diabetes, and cardiovascular disease. Resistin also appears to mediate the pathogenesis of atherosclerosis by promoting endothelial dysfunction, vascular smooth muscle cell proliferation, arterial inflammation, and the formation of foam cells. Thus, resistin is predictive of atherosclerosis and poor clinical outcomes in patients with cardiovascular disease and heart failure. Furthermore, recent evidence suggests that resistin is associated with atherogenic dyslipidemia and hypertension. The present review will focus on the role of human resistin in the pathogeneses of inflammation and obesity-related diseases.
Assuntos
Doenças Cardiovasculares/etiologia , Inflamação/etiologia , Doenças Metabólicas/etiologia , Resistina/fisiologia , Animais , Aterosclerose/etiologia , Humanos , Hipertensão/etiologia , Resistência à Insulina/fisiologia , Camundongos , Obesidade/etiologia , Receptores de Adipocina/fisiologia , Resistina/genéticaRESUMO
The prevalence of obesity is rising worldwide. Recent research findings show that adipose tissue is a highly active endocrine organ, which is involved in many physiological processes. These metabolic processes are influenced by products of the adipose tissue, so-called adipokines, which play a crucial role in the pathogenesis of the metabolic syndrome and cardiovascular disease. In addition, the two major fat depots - intraabdominal and subcutaneous - differ in their ability to secrete adipokines. In recent years the importance of the association between intraabdominal fat and the development of insulin resistance, diabetes mellitus type 2 and dyslipidemia was recognized. Therefore, accumulation of visceral adipose tissue contributes due to its ability to secrete a different pattern of adipokines to increased morbidity and mortality. This review aims to characterize novel, newly recognized adipokines and to discuss their roles in the pathogenesis of insulin resistance and atherosclerosis, as well as other metabolic complications.
Assuntos
Adipocinas/fisiologia , Aterosclerose/fisiopatologia , Resistência à Insulina/fisiologia , Obesidade Abdominal/fisiopatologia , Adipócitos/fisiologia , Adiponectina/fisiologia , Animais , Apelina , Encéfalo/fisiopatologia , Doenças Cardiovasculares/fisiopatologia , Quimiocinas/fisiologia , Fator D do Complemento/fisiologia , Citocinas/fisiologia , Diabetes Mellitus Tipo 2/fisiopatologia , Proteínas de Ligação a Ácido Graxo/fisiologia , Feminino , Proteínas Ligadas por GPI/fisiologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Lectinas/fisiologia , Masculino , Síndrome Metabólica/fisiopatologia , Receptores de Adipocina/fisiologia , Resistina/fisiologia , Proteínas Plasmáticas de Ligação ao Retinol/fisiologia , Serpinas/fisiologiaRESUMO
Scientific results in the past fifteen years have proven that adipose tissue is an active endocrine organ secreting several hormones. Authors review and discuss the functions of leptin, adiponectin, resistin, visfatin and omentin with special references to metabolic actions.
Assuntos
Adipocinas/metabolismo , Adipocinas/fisiologia , Tecido Adiposo/metabolismo , Tecido Adiposo/fisiologia , Receptores de Adipocina/metabolismo , Receptores de Adipocina/fisiologia , Adipocinas/sangue , Adiponectina/metabolismo , Tecido Adiposo/fisiopatologia , Citocinas/metabolismo , Citocinas/fisiologia , Proteínas Ligadas por GPI , Humanos , Lectinas/metabolismo , Lectinas/fisiologia , Leptina/metabolismo , Fígado/metabolismo , Músculo Esquelético/metabolismo , Nicotinamida Fosforribosiltransferase/metabolismo , Nicotinamida Fosforribosiltransferase/fisiologia , Pâncreas/metabolismo , Receptores de Adiponectina/metabolismo , Receptores para Leptina/metabolismo , Resistina/metabolismoRESUMO
El concepto clásico afirma que el tejido adiposo (TA) es parte del tejido conjuntivo y está compuesto por células que almacenan lípidos llamados adipocitos. La distribución del TA es diferente según los sexos. En las mujeres predomina la distribución ginecoide, mientras que en los varones lo hace en la mitad superior (distribución androide). En el hombre hay un predominio de la grasa visceral, con mayor actividad lipolítica. En cambio, en la mujer se almacena energía y sólo la libera en casos extremos como el embarazo y la lactancia, predominando la lipogénesis. La lipólisis y la lipogénesis son procesos simultáneos y el predominio de uno de ellos determinará la dirección del metabolismo del TA. En la actualidad se considera que el TA blanco constituye, como la piel, un órgano productor de ciertas sustancias- adipoquinas- con acción endocrina, paracrina y autocrina. La gran cantidad de receptores para distintos estímulos explican la sensibilidad y adaptación del TA a las múltiples circunstancia metabólicas.
