THE INDUCTION OF CYCLOOXYGENASE-2 BY INTERLEUKIN-4 IN HUMAN UMBILICALVEIN ENDOTHELIAL-CELLS - A POSSIBLE ROLE IN REGULATION OF FETAL VASCULAR TONE

OBJECTIVE: We sought to determine a possible role for interleukin-4, i n the control of umbilical cord blood flow by evaluating its effect on cyclooxygenase-2 production of a vasoactive prostaglandin. STUDY DESI GN: Human umbilical vein endothelial cells in culture were incubated f or 16 hours in media containing interleukin-4 in concentrations from 5 to 100 ng/ml. Prostaglandin E-2 concentrations in the culture media w ere measured using a monoclonal enzyme-immunoassay. Concentrations of cyclooxygenase-1 and cyclooxygenase-2 were determined by Western blot analysis on cell homogenates. Statistical comparisons between prostagl andin E-2, cyclooxygenase-1, and cyclooxygenase-2 concentrations for e ach interleukin-4 concentration were performed using a one way analysi s of variance. RESULTS: Incubation of human umbilical vein endothelial cells in media containing interleukin-4 resulted in a significant inc rease in both prostaglandin E-2 and cyclooxygenase-2 for interleukin-4 concentrations greater than 50 ng/ml (p < 0.05). Cyclooxygenase-1 lev els were not affected. CONCLUSIONS: We suggest that interleukin-4 may have a role in the regulation of umbilical blood flow mediated through the induction of cyclooxygenase-2.