Oral administration of prostaglandin E2 to humans: effects on peripheral blood leukocyte function.

We examined the effect of small orally administered doses of prostaglandin E2 (0.5 and 1.0 mg) on human peripheral blood leukocyte function. Plasma levels of 13,14-dihydro-15-keto-prostaglandin E2 peaked at 1 hour and returned to baseline at 3 to 4 hours. Adherence of lymphocytes to virus-infected cells was increased significantly 5 hours after ingestion of prostaglandin E2. Increases in adherence were similar to those found when lymphocytes were incubated in vitro with 10(-10) mol/L prostaglandin E2. Thus, this cell-cell interaction is very sensitive to prostaglandin E. Orally administered doses of prostaglandin E2 had only marginal effects on other leukocyte functions (active and total E-rosette formation, lymphocyte proliferation response to mitogen, and monocyte natural cytotoxicity) that are far less sensitive to prostaglandin E in vitro. Prostaglandin E2 clearly has the capacity to influence lymphocyte function when administered orally to normal humans.