Effect And Mechanism Of Liraglutide On Isolated Rat Thoracic Aortic Rings

Objective:To investigate the effect of liraglutide on the rat isolated aorta ring in norepinephrine(NE) pre-contracted condition.Methods and materials:The isolated rat aortic rings were mounted in an organ bath and measured of isometric force. The vasodilation reaction of liraglutide on NE(10-6mol·L-1)-precontracted rings was observed, the effect of liraglutide on the aorta ring pre-contracted by the inhibitors of e NOS-NG-Nitro-L-arginine-Methyl-Ester(L-NAME,.10-4mol·L-1) and ATP-sensitive-potassium(KATP)-Glibenclamide(10-5mol·L-1) was analyzed.Results:Liraglutide(10-5mol·L-1)had no effect on the rat isolated aortic rings in the condition without drug stimulation,however to the precontracted rings with NE(10-6mol·L-1)liraglutide reduced the contraction of endothelium-intact and endothetium-denuded aortic rings in concentration dependent manner,and reduced the endothelial contraction stronger in endothelium-intact aortic rings.The contraction could be partly blocked by pretreatment with L-NAME(10-4 mol·L-1).Conclusion:Liraglutide could bring significant vasodilatation on aorta rings in adult rats which precontracted by NE.The vasodilation of liraglutide was partly associated with endothelium-dependent mechanisms.This mechanism was involved in the synthesis of nitric oxide(NO),but not showed theassociation with the ATP-sensitive-potassium(KATP)-Glibenclamide in the aorta ring.