title: Meconium-stained amniotic fluid activates polymorphonuclear leukocytes ultrastructural and enzyme-cytochemical evidence.
abstract: The purpose of the present study was to demonstrate morphological evidence that meconium-stained amniotic fluid activates polymorphonuclear leukocytes. We used Boyden chamber techniques to determine the chemotactic activity of meconium-stained amniotic fluid for leukocytes, and ultrastructural enzyme-cytochemistry for peroxidase and alkaline phosphatase to characterize the leukocyte features induced by contact with meconium-stained amniotic fluid. Amniotic fluid with meconium staining enhanced migration of leukocytes. These leukocytes exhibited more numerous cytoplasmic processes and more prominent phagosomes compared to peripheral blood leukocytes. Peroxidase and alkaline phosphatase activity were evident on the phagosomal membranes. Our results indicate that meconium-stained amniotic fluid activates or stimulates polymorphonuclear leukocytes. Meconium-stained amniotic fluid induced leukocyte activation might play important roles in the pathophysiology of initiation of term labor or of the meconium aspiration syndrome.
authors.affiliation: Department of Obstetrics and Gynecology, Jichi Medical School, Tochigi, Japan. matsushi@jichi.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Matsubara
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: H
authors.initials: H
authors.lastname: Minakami
authors.forename: T
authors.initials: T
authors.lastname: Takizawa
authors.forename: I
authors.initials: I
authors.lastname: Sato
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000653:Amniotic Fluid / Q000276:immunology*; D002465:Cell Movement / Q000276:immunology; D002478:Cells, Cultured; D002633:Chemotaxis / Q000276:immunology; D003593:Cytoplasm / Q000201:enzymology / Q000648:ultrastructure; D015194:Diffusion Chambers, Culture; D005260:Female; D006801:Humans; D007425:Intracellular Membranes / Q000201:enzymology / Q000648:ultrastructure; D008213:Lymphocyte Activation / Q000276:immunology; D008470:Meconium / Q000276:immunology*; D008854:Microscopy, Electron; D009504:Neutrophils / Q000201:enzymology / Q000276:immunology* / Q000648:ultrastructure; D009195:Peroxidase / Q000378:metabolism; D010588:Phagosomes / Q000201:enzymology / Q000648:ultrastructure; D011247:Pregnancy
chemical_list: D009195:Peroxidase; D000469:Alkaline Phosphatase