Prostaglandins: an overview.

Since their discovery more than 40 years ago, PGs have been shown to be present in many tissues. The 10 members of this family (PGA-PGI and TxA) that have been identified to date have been noted to have a wide variety of pharmacologic actions. Frequently, the actions of one PG are in direct opposition to those of another. This has led to the theory that PGs play an important role in maintaining homeostasis in many organ systems. Evidence accumulated indicates a major role for PGs in the regulation of blood pressure, the autonomic nervous system, blood flow and platelet aggregation. This is in addition to specific actions on other tissues such as the CNS and reproductive system. A summary of PG actions in humans is contained in Table 1. Unfortunately, the PGs have not been as useful therapeutically as originally hoped. Currently, they are being used to induce labor and to maintain the patency of the PDA. However, they still hold much promise and with the development of synthetic analogues and specific synthesis inhibitors, they should live up to this promise in the future.