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 may play a role in the toxic effects of prenatal ethanol exposure. Using the novel technique of in utero microdialysis the present study tested the hypothesis that acute ethanol exposure changes PGE concentration in the intact cerebral cortex of preterm (93 ± 1 days of gestation) and near-term (124 ± 1 days or gestation; term, ~147 days) fetal sheep. Fetal sheep were surgically instrumented with a microdialysis probe place in the parasagittal parietal cortex. There 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 cortical and plasma PGE concentrations were determined. In the preterm fetal cerebral cortex, PGE concentration was in creased after ethanol infusion in all six animals studied. The median peak increase was 160% with a 95% confidence interval of 115 to 784%. There was considerable variation in the time of occurrence, magnitude, and duration of this increase. In the near-term fetal cerebral cortex, an increase in PGE concentration was observed after ethanol infusion in 6 of the 7 animals studied, whereas a decrease in PGE concentration was observed in the other two animals. Overall, ethanol did not increase significantly near-term fetal cerebral corti cal PGE concentration. For both age groups, ethanol infusion had no effect on fetal plasma PGE concentration. These data indicate that ethanol can affect PGE production in the fetal cerebral cortex and that this effect seems to be gestational-age-dependent.