The document summarizes the chemical mediators released during acute inflammation. These mediators include histamine, prostaglandins, nitric oxide, complement fragments, leukotrienes, interleukin-1, tumor necrosis factor, platelet activating factor, and chemokines. They promote vasodilation, increased vascular permeability, chemotaxis, leukocyte recruitment, fever, pain, and tissue damage. The mediators are released from mast cells, leukocytes, macrophages, and the complement system in response to injury or infection.