Punicic Acid Induces Endothelium-Dependent Vasorelaxation in Rat Thoracic Aortic Rings

Abstract

Objective: The aim of the present study was to investigate the possible mechanism by which pomegranate seed oil causes vasodilatation in isolated thoracic aorta rings form the rat. Material and Methods: The isolated rat arteries were cut into rings and placed in tissue chambers filled with Krebs solution. results: Pomegranate seed oil produced a concentration-dependent relaxation in rings with endothelium. However, it didn't cause any relaxant effect in the absence of endothelium. L-NAME and ODQ produced a significant inhibition in the rings with endothelium. Subsequent addition of L-arginine reversed the inhibitory effects of L-NAME. However, the relaxant effect of PSO did not change with tetraethylammonium, 4-aminopyridine and glibenclamide, in rings either with or without endothelium. Additionally, the relaxant effect of PSO was not affected by indomethacin, propranolol, losartan or captopril incubation. In another set of experiments rats were anaesthetised and surgically equipped with intraperitoneal radio-transmitters to record blood pressure in vivo. PSO caused a slight decrease in systolic and diastolic blood pressure along with mildly decreased heart rate. conclusion: These comprehensive findings clearly indicate that vasorelaxation is induced by PSO via modulation of nitric oxide-guanylyl cyclase pathway.