Leptin at gender-specific concentrations does not affect glucose transport, expression of glucose transporters and leptin receptors in human lymphocytes

Leptin shows pleiotropic effects in organisms including an important role in the regulation of glucose homeostasis. Elevated serum leptin, particularly in obese individuals, is a warning sign of energy imbalance, hyperinsulinemia, insulin resistance and other metabolic risk factors that are strongly associated with type 2 diabetes. Obesity is also related to a higher rate of infections and immune function deterioration may in part ensue from decreased glucose uptake as the main energy source for lymphocytes. The aim of this study was to investigate the effect of physiologic and low pathophysiologic gender-specific leptin concentration found in lean and obese subjects on glucose transport, the expression of glucose transporters and leptin receptors in human peripheral blood lymphocytes. Isolated lymphocytes were incubated with human leptin at gender-specific concentrations observed in normal weight and obese subjects. Glucose uptake in lymphocytes was determined using nonmetabolizable radiolabeled deoxy-d-glucose. The expression of GLUT1, 3, 4 and leptin receptors was investigated using methods of immunocytochemistry and flow cytometry. Leptin at concentrations used in the study does not change glucose transport into lymphocytes and seems to have no influence on the expression of glucose transporters and leptin receptors. Further studies are necessary to address the relationship between leptin, glucose transport and the lymphocytes’ function in obesity.