title: Placental tissue levels of nonesterified polyunsaturated fatty acids in normal and preeclamptic pregnancies.
abstract: OBJECTIVE
  We previously reported that maternal plasma levels of nonesterified polyunsaturated fatty acids were decreased in women with preeclampsia as compared to women with normal pregnancies. Polyunsaturated fatty acids of the n-6 and n-3 families are essential dietary fatty acids. The n-6 polyunsaturated fatty acids are involved in inflammatory reactions, whereas n-3 polyunsaturated fatty acids protect against inflammation.
  
  
  METHODS
  In this study, we investigated the composition of nonesterified polyunsaturated fatty acids in placental tissue of normal and preeclamptic pregnancies. Linoleic (18:2) and arachidonic (20:4, AA) acids of the n-6 family and linolenic (18:3), eicosapentaenoic (20:5, EPA) and docosahexaenoic (22:6, DHA) acids of the n-3 family were analyzed.
  
  
  CONCLUSIONS
  We found that total concentrations of nonesterified polyunsaturated fatty acids were lower in placental tissues from preeclamptic pregnancies than from normal pregnancies. Both n-6 and n-3 polyunsaturated fatty acids were decreased. The decrease in n-6 polyunsaturated fatty acids was due to a decrease in AA. The concentration of linoleic acid was not altered. For n-3 polyunsaturated fatty acids, DHA was decreased, with no change in linolenic acid. The percentage decrease in EPA and DHA was greater than for AA, so the ratio of n-6 to n-3 polyunsaturated fatty acids was two-fold higher in preeclampsia than normal pregnancy. Because the levels of essential fatty acids, linoleic (18:2) and linolenic (18:3), are preserved but levels of metabolites (AA and DHA) are reduced, we speculate that placental oxidative stress and increased conversion of AA to thromboxane are responsible for the decreased concentrations of polyunsaturated fatty acids in preeclampsia.
authors.affiliation: Department of Obstetrics and Gynecology, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130, USA. ywang1@lsuhsc.edu
authors.forename: Yuping
authors.initials: Y
authors.lastname: Wang
authors.forename: Scott W
authors.initials: SW
authors.lastname: Walsh
authors.forename: Helen H
authors.initials: HH
authors.lastname: Kay
mesh_terms: D000328:Adult; D002851:Chromatography, High Pressure Liquid; D005230:Fatty Acids, Nonesterified / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D005260:Female; D006801:Humans; D010920:Placenta / Q000378:metabolism*; D011225:Pre-Eclampsia / Q000378:metabolism*; D011247:Pregnancy; D018709:Statistics, Nonparametric
chemical_list: D005230:Fatty Acids, Nonesterified; D005231:Fatty Acids, Unsaturated