ABSTRACT
The aim of this work is to evaluate the hemodynamic changes of leptin administration to rabbits. A total of 18 male New Zealand rabbits, weighing from 1 to 1.5 kg were included in this study. After induction of anesthesia, basal arterial blood pressure [Am, sodium [Na+], potassium [K+] and creatinine concentrations in both blood and urine samples were evaluated. The animals were then randomly assigned to 3 groups of 6 each. Group I [control] received isotonic saline by intravenous infusion. Group II [study group] received intra-arterial injection of leptin [10 micro g/kg] for one Hour followed by a 10-Jold higher dose of leptin. Group III [negative control] received intravenous bolus injection of propranolol [0.1 mg] for one hour followed by a similar dose for the next hour. Administration of leptin resulted in slight increase in mean arterial pressure [MAP] that reached significance after 90 min and persisted above the basal level for the recording period of 2 hours. There were no parallel changes, at either doses, infraction reabsorption of Na+, K+, H20 and glomerular filtration rate [GFR] as compared to both basal values and to control animals. It was concluded that the elevation in MAP induced by leptin was most probably not related to renal mechanism, as there were no significant changes in renal parameters studied. This suggests another mechanism for the rise in MAP, a suggestion which needs further studies