PROSTAGLANDIN E₁, ASPIRIN AND THE ACTION OF LEUKOCYTIC ENDOGENOUS MEDIATOR

¹ Biomedical Division, The Samuel Roberts Noble Foundation, Inc., Ardmore, Oklahoma

Leukocytic endogenous mediator (LEM) induces numerous changes typical of those seen during the acute phase of inflammation. The possibility that LEM was acting through prostaglandin E₁ (PGE₁) was investigated. PGE₁ failed to mimic the effects of LEM when injected intracisternally or intravenously. Injection of PGE₁ intracisternally increased temperature in rats whereas injections of LEM produced hypothermia. Aspirin, an inhibitor of prostaglandin synthesis, did not block LEM induced release of neutrophils from the bone marrow or the lowering of plasma iron levels. The combination of these two findings plus the variety of routes used to administer both PGE₁ and aspirin make it unlikely that PGE₁ is involved in either lowering of plasma iron or the release of neutrophils from the bone marrow during the acute phase of inflammation.