Leukotrienes are naturally prouced eicosanoid lipid mediators, which may be responsible for the effects an inflammatory response. Leukotrienes use both autocrine signalling and paracrine signalling to regulate the body's response. Leukotrienes are produced in the body from arachidonic acid by the enzyme 5-lipoxygenase. Their production by the body is part of a complex response that usually includes the production of histamine.