Özet:

Purpose: This study has studied the effects of leptin on the basal tone of the isolated human umbilical artery and the accumulation responses associated with hydrogen peroxide (H2O2) and the role of nitric oxide in these effects.Therms and methods: The umbilical artery rings were taken into 10 ml isolated organ baths with a mixture of 95% O2-% 5CO2 and containing the Krebs-Henseleit solution. The responses to the procedures applied were recorded isometrically. In the section where the effects of leptin on the basal tone of the umbilical artery rings were studied, leptin (10-11-10-7 M) applied to the bath in a cumulative way did not affect the basal tone of the tissues. Similarly, in tissues incubated with L-NAME (10-4 M), the accumulative leptin supplement does not change the basal tone of the tissues. In the umbilical artery rings, the maximum cumulative response with H2O2 (10-3 M) was obtained and the relaxation response was created depending on the concentration of leptin, which was accumulatively applied to the body bath. The addition of 10-4M L-NAME to the body bath has not affected the relaxation responses observed in the concentrations of 10-11 and 10-10M of leptin on the H2O2-related cumulative responses; the relaxation responses of leptin to the umbilical arterial stripes in the concentrations of 10-9,10-8 and 10-7 M have been substantially inhibited. In the section where the effects of H2O2 in the umbilical arterial rings incubated with leptin, the incubation of tissues with 10-10 M and 10-7 M leptin did not change the pD2 (-log EC50) and Emax values of H2O2 accumulated. Results: These findings show that leptin in all concentrations applied to the human umbilical artery has a relaxing effect on the H2O2-related cumulative responses, that leptin is partially mediated by NO to the relaxing responses observed in high concentrations, and that leptin does not have an inhibitor effect on the basal tone of the umbilical arteries and the H2O2-related cumulative responses applied at the basal tone.