Eicosanoids
introduction
Eicosanoids are hormones that act as nerve transmitter substances (Neurotransmitters) and modulators of the immune system work. These hormones also have a role to play in inflammatory processes.
Overall, one differentiates between the following types of eicosanoids:
- Prostaglandins
- Prostacyclines (Part of the prostaglandins)
- Thromboxanes (Part of the prostaglandins)
- Leukotrienes
The prostaglandins comprise a large number of subgroups, for example prostaglandin D2, prostaglandin E2, prostglandin I2 (prostacyclin) or thormboxanes.
education
Formation of Eicosanoids:
The Eicosanoids are formed from the fatty acid arachidonic acid, which is converted into the definitive hormones by enzymes in the following synthesis steps.
The enzymes responsible for producing hormones include Cxclooxygenase (COX, prostaglandins), the Prostacyclin synthase (Prostacyclin), the Lipoxygenase (Leukotrienes) and thromboxane synthase (thromboxanes).
Prostaglandin synthesis takes place in many organs, as does prostacyclin and thromboxane formation. Leukotrienes are found in white blood cells (Leukocytes) and in the phagocytes (Macrophages) manufactured.
Each of these hormones has its own receptors.
regulation
Regulation of the Eicosanoids:
Prostaglandins, prostacyclines and thromboxanes are released in a tissue-specific manner. For example, inflammation, reduced blood flow (Ischemia) or cell damage; Glucocorticoids have an inhibitory influence. The most important stimulators of leukotriene release are inflammatory stimuli.
function
In their function as hormones, eicosanoids have a broad spectrum of activity. The single ones Prostaglandins sometimes have the opposite effect (antagonistic).