Evolution of ideas on the role of prostaglandins in inflammation.

Anti-inflammatory activity is found among compounds which in vitro inhibit (aspirin), stimulate (chlorpromazine) or have no effect on (hydrocortisone) biosynthesis of primary prostaglandins. On the other hand some in vitro stimulators of prostaglandin biosynthesis (e.g. pyrazol(3,4b)-pyridine derivatives) are pro-inflammatory agents. It is concluded that primary prostaglandins do not play a pivotal role in inflammatory response.