title: Amniotic fluid lipoxygenase metabolites during spontaneous labor and after RU486 treatment during late pregnancy in rhesus macaques.
abstract: To determine changes in amniotic fluid (AF) lipoxygenase metabolites prior to spontaneous labor and after RU486 administration, we implanted AF and vascular catheters and myometrial electromyographic (EMG) electrodes in 8 rhesus macaques at 120-130 days of pregnancy (term = 167 days). Four animals had AF samples taken serially until they delivered their infants normally at term. The other four animals received RU486 (20 mg/kg/day) for 3 days. AF samples were collected every 2-3 days and at 12 hour intervals for 72 hours before and after treatment with RU486. Uterine activity was monitored continuously. LTB4, 5-HETE and 15-HETE were measured by radioimmunoassay. In untreated animals, LTB4 and 5-HETE concentrations in AF increased significantly (P less than 0.05) 4 days before delivery with no change in 15-HETE. After RU486, mean levels of LTB4 and 5-HETE were increased although the difference was not statistically significant. No change in 15-HETE levels was observed. In conclusion, LTB4 and 5-HETE increase in AF before the onset of spontaneous labor. Progesterone receptor blockade by RU486 does not reproduce the changes in AF lipoxygenase metabolites observed during normal parturition.
authors.affiliation: Division of Reproductive Biology & Behavior, Oregon Regional Primate Research Center, Beaverton 97006.
authors.forename: G J
authors.initials: GJ
authors.lastname: Haluska
authors.forename: M D
authors.initials: MD
authors.lastname: Mitchell
authors.forename: M J
authors.initials: MJ
authors.lastname: Novy
mesh_terms: D000653:Amniotic Fluid / Q000378:metabolism*; D000818:Animals; D005260:Female; D007743:Labor, Obstetric / Q000378:metabolism*; D008084:Lipoxygenase / Q000378:metabolism*; D008253:Macaca mulatta; D015735:Mifepristone / Q000494:pharmacology*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000187:drug effects* / Q000378:metabolism
chemical_list: D015735:Mifepristone; D008084:Lipoxygenase