Distribution of Components of the Glutathione Detoxification System Across the Human Placenta after Uncomplicated Vaginal Deliveries

Abstract

The function of the glutathione-related detoxification system plays an important role to ensure an uncomplicated pregnancy outcome. This study was performed to investigate whether the components of the glutathione-related detoxification system are equally distributed among the different cotelydons in the human placenta. We measured glutathione, cysteine, glutathione S-transferase (GST) isoenzyme levels (GSTA1+A2, GSTP1, GSTM1 and GSTT1), enzyme activities of glutathione S-transferase and glutathione peroxidases, protein carbonyl levels, and antioxidant capacities at twelve different standardized positions in six placentae from healthy women after uncomplicated pregnancy and vaginal delivery. Data were statistically evaluated with a Friedman two-way ANOVA with Bonferroni correction. ‘Foetal’-side values were not significantly different from those at the ‘maternal’-side. Except for GSTA1+A2, no significant differences were found between different sampling sites indicating that the distribution of all parameters measured was homogenous throughout the placenta. Since levels of GSTA1+A2 were minor compared to those of GSTP1 and GSTT1, the clinical relevance of this heterogeneity may be limited. These results implicate that the location of sampling is not important as long as biopsies are taken from physiological cotelydons.