Prostaglandin
Prostaglandins are members of a group of lipid compounds that are derived enzymatically from essential fatty acids (EFAs) and have important functions in the animal body. Every prostaglandin contains 20 carbon atoms, including a 5-carbon ring.
Prostaglandins thus act on a variety of cells such as vascular smooth muscle cells causing constriction or dilation, on platelets causing aggregation or disaggregation and on spinal neurons causing pain. Prostaglandins have a wide variety of actions, including, but not limited to muscular constriction and mediate inflammation. Other effects include calcium movement, hormone regulation and cell growth control.