All of the following inflammatory mediators produce vasoconstriction except

Kinins including Bradykinin cause contraction of visceral smooth muscle, but they relax vascular smooth muscle NO, lowering blood pressure. Thromboxane A2 promotes platelet aggregation and vasoconstriction Platelet-activating factor (PAF), a cytokine secreted by neutrophils and monocytes as well as platelets. This compound also has inflammatory activity. It is an ether phospholipid, 1-alkyl-2acetylglyceryl-3-phosphorylcholine, which is produced from membrane lipids. It acts a G protein-coupled receptor to increase the production of arachidonic acid derivatives, including thromboxane A2 which cause vasoconstriction Endothelial cells produce endothelin-1, one of the most potent vasoconstrictor agents yet isolated Ref: Ganong's Review of Medical Physiology Twenty-Third Edition Page No:566