Adiponectin: novelties in metabolism and hormonal regulation.
Adiponectin is a protein secreted exclusively by white adipose tissues and is abundantly present in human plasma. Adiponectin was found decreased in obese and diabetes mellitus type 2 patients and increased with weight reduction. A negative correlation between circulating adiponectin levels and body mass index and insulin resistance has been demonstrated. Plasma adiponectin concentrations were found lower in diabetes mellitus type 2 patients with coronary artery disease. Moreover, studies in aortic endothelial cells revealed that the protein exerts a dose-dependent decrease of the surface expression of vascular adhesion molecules and cytokine production from macrophages, suggesting the implication of adiponectin in atherosclerosis and inflammation. Weight loss and treatment with thiazolidinediones stimulate endogenous adiponectin production. Peripheral administration of adiponectin leads to reduction of visceral adiposity and increase of free fatty acid oxidation and insulin resistance. Furthermore, it enhances the expression of uncoupling proteins and sympathetic nerve activity in adipose tissues. Experimental studies in mice have shown that intraperitoneal administration of adiponectin lowers plasma glucose. These data show adiponectin to be an important factor in the issue of obesity and its associated disorders, and indicate a potential future utilization of adiponectin as a drug in the treatment of metabolic syndrome.
Duntas
Leonidas H
LH
Evgenidion Hospital, University of Athens, 11528 Athens, Greece. ledunt@otenet.gr
Popovic
Vera
V
Panotopoulos
George
G
D052242:Adiponectin; D000273:Adipose Tissue; D000818:Animals; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2; D004734:Energy Metabolism; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D006728:Hormones / Q000502:physiology*; D006801:Humans; D007333:Insulin Resistance; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000502:physiology* / Q000627:therapeutic use; D008060:Lipodystrophy; D024821:Metabolic Syndrome / Q000628:therapy; D009765:Obesity; D010084:Oxidation-Reduction
D052242:Adiponectin; D005230:Fatty Acids, Nonesterified; D006728:Hormones; D036341:Intercellular Signaling Peptides and Proteins