AIMS Leptin plays an important role in the pathogenesis of obesity and diabetes, yet the regulatory mechanisms of this hormone have not been fully elucidated. In this study, we aimed to clarify the roles of insulin and glucose in leptin secretion and mRNA production using inhibitors of insulin signal transduction in adipocytes cultured under glucose-free or normal conditions. METHODS Differen...

Background and Aim. Leptin has two forms in the circulation: free and bound forms. The soluble leptin receptor (sOB-R) circulates in the blood and can bind to leptin. The aim of this study is to assess the concentrations of the leptin and the sOB-R in PCOS and its relation to adiposity, insulin resistance, and androgens. Methods. A cross-sectional study included 78 female students aged 17-25 ye...

A common -2548G/A promoter variant of the human leptin gene has recently been shown to be associated with variations in circulating leptin levels but available data are still conflicting. The aim of this study was to explore potential associations between the -2548G/A polymorphism and adiposity-related variables, plasma total leptin levels, as well as soluble leptin receptor (sOB-R) levels and ...

Leptin, the product of obese gene, was originally identified as a factor regulating body-weight homeostasis and energy balance. The present study has shown that leptin acts on murine hematopoiesis in vitro. In the culture of bone marrow cells (BMC) of normal mice, leptin induced only granulocyte-macrophage (GM) colony formation in a dose-dependent manner, and no other types of colonies were det...

To investigate soluble leptin receptor (sLR) in plasma, specific anti-sLR monoclonal antibodies were developed. Western blot analysis and size exclusion fractionation demonstrated sLR in plasma with a molecular mass of approximately 180,000. Next to this, the presence of sLR-leptin complexes in plasma was confirmed. Using the developed monoclonal antibodies, a specific sLR ELISA was developed, ...

It has been suggested that increased fructose intake is associated with obesity. We hypothesized that chronic fructose consumption causes leptin resistance, which subsequently may promote the development of obesity in response to a high-fat diet. Sprague-Dawley rats were fed a fructose-free control or 60% fructose diet for 6 mo and then tested for leptin resistance. Half of the rats in each gro...

Obesity is an established risk factor for breast cancer in post-menopausal women, being associated with elevated serum levels of leptin. Although overweight a common condition cat, the role leptin and its receptor feline mammary carcinoma remains unsettled. In this study, (ObR) were investigated 58 cats compared those healthy animals, as expression ObR tumor tissues. The results showed that Fre...

Little is known about leptin's interaction with other circulating proteins which could be important for its biological effects. Sephadex G-100 gel filtration elution profiles of 125I-leptin-serum complex demonstrated 125I-leptin eluting in significant proportion associated with macromolecules. The 125I-leptin binding to circulating macromolecules was specific, reversible, and displaceable with ...