Fetal surfactant as a source of arachidonate in human amniotic fluid.
The factors responsible for the onset of labor in women are not well understood but it is clear that parturition is associated with increased production of prostanoids and release of arachidonic acid by intrauterine tissues. Pulmonary surfactant is secreted from the fetal lung into the amniotic fluid where its concentration increases toward term. In this paper we have shown that the ability of fetal surfactant to stimulate prostaglandin production by amnion cells is greatly enhanced by pre-incubating surfactant with amniotic fluid. This is due to the release of fatty acids, including arachidonate, from the lipids of fetal surfactant by the sequential action of phospholipase C and diglyceride lipase. Thus, in addition to providing the amnion with a source of arachidonate derived from the intracellular transfer of arachidonate from surfactant phosphatidylcholine to phosphatidylethanolamine and phosphatidylinositol in amnion cells, fetal surfactant also contributes to the pool of free arachidonate in amniotic fluid.
Bernal
A L
AL
Nuffield Department of Obstetrics and Gynaecology, John Radcliffe Hospital, Women's Centre, Headington, UK. alb@ermine.ox.ac.uk
Phizackerley
P J
PJ
D000653:Amniotic Fluid / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D016718:Arachidonic Acid / Q000378:metabolism*; D002250:Carbon Radioisotopes; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D006801:Humans; D050356:Lipid Metabolism; D008071:Lipoprotein Lipase / Q000378:metabolism; D010713:Phosphatidylcholines / Q000737:chemistry; D011247:Pregnancy; D011453:Prostaglandins / Q000378:metabolism; D011663:Pulmonary Surfactants / Q000378:metabolism*; D010738:Type C Phospholipases / Q000378:metabolism
D002250:Carbon Radioisotopes; D005227:Fatty Acids; D010713:Phosphatidylcholines; D011453:Prostaglandins; D011663:Pulmonary Surfactants; C043644:1-stearoyl-2-arachidonylphosphatidylcholine; D016718:Arachidonic Acid; D008071:Lipoprotein Lipase; D010738:Type C Phospholipases