Eicosanoid agonists

Alternatively, the release of platelet phospholipid AA is mediated by the activation of phospholipase Aj (PIA) coupled to PLC, intracellular Ca rise and protein kinase C (PKC) and tyrosine kinase-mediated protein phosphorylations (23,24) and/or by the activation of PLA that is not coupled to these events in platelets (25-29). Furthermore, the hydrolysis of phosphatidic acid (PA) by a PA-specific PLAj may also contribute to eicosanoid synthesis (30,31). It is evident that the differential sensitivity of platelets to multiple agonists and their signals, have contributed to the complexity in understanding the regulation of PLAj. 

LEUKOTRIENE RECEPTOR AGONISTS act at receptors recognizing leukotrienes and analogues. The lipoxygenase system forms the leukotrienes, which are members of the eicosanoid family of phospholipid mediators. Their name derives from the fact that leukotrienes are found in leucocytes and contain a triene system of double bonds. The other members of the eicosanoid family are the prostanoids (thromboxanes and the prostaglandins), and these are formed by the cyclooxygenase system see cyclooxygenase INHIBITORS. All the eicosanoids are derived mainly from arachidonic acid. These mediators are synthesized on demand, and in some cases their half-lives are short. The... 

---