Leukotrienes

Leukotrienes are formed from arachidonic acid and are active as tissue hormones. They act as mediators in inflammatory and allergic reactions in the body by attracting neutrophils leukocytes, increasing vascular permeability and triggering asthma attacks via bronchoconstriction.

https://de.wikipedia.org/wiki/Leukotriene _{(Wikipedia CC-by-sa-3.0)}