Effects of endotoxins and cytokines on the secretion of platelet-activating factor-acetylhydrolase by human decidual macrophages.
OBJECTIVE
The aim was to clarify the role of platelet-activating factor in parturition, preterm labor, and premature rupture of membranes.


METHODS
Decidual macrophage populations were obtained by enzymic digestion, Ficoll-Paque centrifugation, or flow cytometric sorting. The effects of endotoxins and cytokines on platelet-activating factor-acetylhydrolase secretion by these cells were examined.


RESULTS
Lipopolysaccharide inhibited the platelet-activating factor-acetylhydrolase secretion by decidual macrophages. The inhibition was partially reversed by interleukin-1 receptor antagonist or by neutralizing antibodies against interleukin-1 alpha, interleukin-1 beta, or tumor necrosis factor-alpha. Tumor necrosis factor-alpha, interleukin-1 alpha, and interleukin-1 beta also decreased the enzyme secretion. The inhibitory actions of tumor necrosis factor-alpha and interleukin-1 beta were specifically neutralized by the corresponding antibodies. The effect of interleukin-1 alpha or interleukin-1 beta on the secretion was abolished by interleukin-1 receptor antagonist.


CONCLUSIONS
It is suggested that platelet-activating factor is involved in the pathogenesis of preterm labor or premature rupture of membranes caused by endotoxins and the subsequent activation of cytokine network.
Narahara
H
H
Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235-9051.
Johnston
J M
JM
D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase; D000704:Analysis of Variance; D001667:Binding, Competitive; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology*; D003656:Decidua / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D004305:Dose-Response Relationship, Drug; D004731:Endotoxins / Q000494:pharmacology*; D004926:Escherichia coli; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000201:enzymology*; D010741:Phospholipases A / Q000378:metabolism*; D010972:Platelet Activating Factor / Q000502:physiology; D011247:Pregnancy; D017472:Receptors, Interleukin-1 / Q000037:antagonists & inhibitors / Q000502:physiology; D012044:Regression Analysis; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D016207:Cytokines; D004731:Endotoxins; D007375:Interleukin-1; D010972:Platelet Activating Factor; D017472:Receptors, Interleukin-1; D014409:Tumor Necrosis Factor-alpha; D010741:Phospholipases A; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase