Pathology General 6c15dec0 Vasoconstricting mediator is? A Prostacyclin B Thromboxane-A2 C PG D2 D Lipoxins High-Yield Explanation Ans. is 'b' i.e., Thromboxane-A2 Thromboxane-A2 causes vasoconstriction. Other three mediators (given in question) cause vasodilatation.