Basophils and mast cells.

they are amino acid base chemicals made by allergy or immune mediator cells. Leukotrienes are believed to be the causative chemicals in delayed hypersensitivity and are also known as slow reacting substances of anaphylaxis.

Leukotrienes are a family of eicosanoid inflammatory mediators produced in leukocytes by the oxidation of arachidonic acid by the enzyme arachidonate 5-lipoxygenase.

As their name implies, leukotrienes were first discovered in leukocytes, but have since been found in other immune cells.

Any of a group of biologically active compounds, originally isolated from leukocytes. They are metabolites of Arachidonic acid, containing three conjugated double bonds.

A chemical mediator is histamine, leukotrienes, and cytokines that limit the amount of exduate (or stuff your body doesn't want) causing the muscle to swell after injury.