ETHANOL-INDUCED CHANGES IN PROSTAGLANDIN-E CONCENTRATION IN THE INTACT CEREBRAL-CORTEX OF PRETERM AND NEAR-TERM FETAL SHEEP

Ethanol-induced changes in fetal prostaglandin E (PGE) concentration m ay play a role in the toxic effects of prenatal ethanol exposure. Usin g the novel technique of in utero microdialysis, the present study tes ted the hypothesis that acute ethanol exposure changes PGE concentrati on in the intact cerebral cortex of preterm (93 +/- 1 days of gestatio n) and near-term (124 +/- 1 days of gestation; term, similar to 147 da ys) fetal sheep. Fetal sheep were surgically instrumented with a micro dialysis probe placed in the parasagittal parietal cortex. Three days later, the effects of maternal infusion of 1 g of ethanol/kg maternal body weight on preterm (n = 6) and near-term (n = 7) fetal cerebral co rtical and plasma PGE concentrations were determined. In the preterm f etal cerebral cortex, PGE concentration was increased after ethanol in fusion in all six animals studied. The median peak increase was 160% w ith a 95% confidence interval of 115 to 784%. There was considerable v ariation in the time of occurrence, magnitude, and duration of this in crease. In the near-term fetal cerebral cortex, an increase in PGE con centration was observed after ethanol infusion in 5 of the 7 animals s tudied, whereas a decrease in PGE concentration was observed in the ot her two animals. Overall, ethanol did not increase significantly near- term fetal cerebral cortical PGE concentration. For both age groups, e thanol infusion had no effect on fetal plasma PGE concentration. These data indicate that ethanol can affect PGE production in the fetal cer ebral cortex and that this effect seems to be gestational-age-dependen t.