Effect of Intra-Venous Versus Intra-Arterial Leptin Infusion on Blood Pressure and Heart Rate

Objectives: In this study the effects of different Leptin concentrations on the blood pressure and heart rate in vivo in anesthetized rabbits were studied. Methods: Sixty Rabbits were divided into two groups, first group received Leptin intra-venously and other group received Leptin intra-arterially. Blood pressure and heart rate in were recorded before and after administration of Leptin. Results: A significant increase in mean arterial blood pressure (MABP) was seen after an intra-arterial injection of 3, 5 and 7 � g/kg of Leptin. This increase in MABP was monitored for different durations 10, 20 and 30 minutes after the infu- sion of each Leptin concentrations. The trend of the increase in MABP with time was demonstrated with all three concen- trations. Intra-venous infusion of Leptin caused a significant decrease in MABP after 10 minutes as well as after 20 and 30 minutes, with all three concentrations (3, 5, and 7 μg/Kg). Heart rate (HR) was not changed significantly at the end of 30 min of infusion. Conclusion: this in vivo study demonstrated that intra-venous Leptin infusion has a different effect on the MABP com- pared with intra-arterial infusion and this difference might be due to the site of action of Leptin.