Leptin enhances peroxide production in human umbilical cord leucocytes

We have used flow cytometry to assess the effect of human recombinant lepti n on peroxide production by human umbilical leucocytes in cord blood from 1 2 normal newborns (seven females and five males). Peroxide production was d etermined by the oxidation of 2', 7' dichlorofluorescein diacetate (DCFH-DA ) in the three cell populations studied. The cells were stimulated with an optimal and physiological concentration of leptin (10 ng/ml), which induced a constant and significant production of peroxide as compared to non-stimu lated cells. There was a significant two-fold increase (P < 0.005) in perox ide formation at time points 10, 20 and 30 min for polymorphonuclear cells and lymphocytes. Monocytes, in very low number as compared to the other cel l populations, were also activated by leptin. However, the effect on peroxi de production was far below the amount observed when PMA was used as a stim ulus (P < 0.00001). There was no significant correlation between the weight or sex of the newborn and the effect of leptin. Future studies should asce rtain the role of this cytokine in cord blood cells. Med Sci Res 27:245-246 (C) 1999 Lippincott Williams & Wilkins.