The eicosanoids (prostaglandins, thromboxanes, and leukotrienes) have numerous effects on the body.

Prostaglandins and Thromboxanes act like local hormones

• PGE stimulates adenylate cyclase in some cells.
• PGF2 has been reported to elevate levels of cGMP in target cells.
• Inhibition of the cyclooxygenase of PGH synthase by aspirin reduces inflammation, implicating prostaglandins in inflammation.
• Thromboxane A2 and, to a lesser extent, prostaglandins, induce platelet aggregation, an early step in blood clot formation.
• Prostaglandin release is involved in uterine muscle contraction-PGF2 is used to induce labor.
• PGF2 inhibits progesterone secretion and regression of the corpus luteum.
• PGF2 and PGE2 are used to induce abortion in the second trimester or to induce delivery in case of the death of a fetus.
• PGI2 is used to reduce the risk of blood clotting during cardiopulmonary bypass operations.
• PGE1 is a vasodilator.
• Forms of PGE inhibit gastric secretion.

Leukotrienes

• Receptors for leukotriene B4 may be involved in inflammation.
• Leukotrienes may play a role in asthma attacks.

1. Eicosanoids

2. Prostaglandin and Leukotriene Metabolism