Prostaglandins are naturally occurring hormone-like substances that participate in a wide range of body functions including the contraction and relaxation of smooth muscle, the dilation and constriction of blood vessels, control of blood pressure, and modulation of inflammation.

Prostaglandins are derived from a chemical called arachidonic acid and are most known for their impact on increasing inflammation and thrombosis (clot formation).

The prostaglandins together with the thromboxanes and prostacyclins form the prostanoid class of fatty acid derivatives; the prostanoid class is a subclass of eicosanoids. Types of prostaglandins include: Prostaglandin D2 (PGD2), Prostaglandin E2 (PGE2) and Prostaglandin F2a (PGF2a).

References

The Prostaglandin Collection, Floida State University: http://micro.magnet.fsu.edu/micro/gallery/prostaglandin/prostaglandin.html