<prompt> All of the following inflammatory mediators produce vasoconstriction exceptEndothelin-1BradykininThromboxane A2Platelet activating factor  <response>: 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: Ganongs Review of Medical Physiology Twenty-Third Edition Page No:566 