Leukotriene receptors

The endogenous ligands for the leukotriene, lipoxin and oxoeicosanoid receptors are bioactive products produced by the action of the lipoxygenase family of enzymes, as depicted in Fig 1 [2,4]. The formation of leukotrienes by 5-lipoxygenase from acid arachidonic acid starts with the epoxide intermediate LTA4, which serves as precursor for leukotriene synthesis (Fig. 1). Subsequent metabolism through the enzyme LTA4 hydrolase leads to the formation of LTB4, which is the ligand for the BLT receptors. Alternatively, the conjugation of LTA4 with glutathione yields the cysteinyl-leukotrienes (Fig 1) acting on CysLT receptors (Fig 1). The leukotriene receptor class also includes receptors for other mediators derived from arachidonic acid through lipoxygenase metabolism, namely the ALX/FPR2 receptor for lipoxin A4 [10], and the OXE receptor for 5-Oxo-ETE [1].