What Do Mast Cells Release That Brings About Localized Vasodilation

Question

What do mast cells release that brings about localized vasodilation in an inflamed area
A)histamine
B)opsonin
C)interleukin 1
D)leukocyte mediator

Accepted Answer

Mast cells release histamine, which is a potent vasodilator. When mast cells are activated, histamine is released and binds to nearby blood vessels, causing them to dilate and become more permeable to allow for the recruitment of immune cells to the inflamed area.