discovered by v. Euler in the seminal fluid and in the - false - assumption that they were formed in the prostate, substances named after it. Prostaglandins are formed in the most diverse body tissues from →Arachidonsäure and unfold there as particularly short-lived intermediate products, already in smallest concentrations various effects; special meaning of the Prostglandine with the local regulation of the blood circulation (inflammation reaction), with endo and exocrine gland function, pregnancy and birth; are considered as membrane-standing protection factors with pathophysiological meaning with pain, fever and inflammation.
It is formed from arachidonic acid by the enzyme cyclooxygenase. The prostaglandins, especially PGE2 and PGE1, have a direct relaxing effect on the vascular muscles. They dilate most vessels and increase their permeability, lowering peripheral resistance and arterial blood pressure. They act as inflammation mediators.
https://de.wikipedia.org/wiki/Prostaglandin (Wikipedia CC-by-sa-3.0)