Tryptophan catabolism and the intrauterine renin-angiotensin system in pregnancy

Indoleamine 2,3-dioxygenase (IDO) and tryptophan (TDO) are key enzymes for (Trp) degradation in the placenta, that is crucial immune tolerance during pregnancy. Intrauterine renin-angiotensin system also involved progression of a healthy Angiotensin (Ang) (1-7) inhibits pro-inflammatory actions Ang II, maintaining integrity fetal membranes. Since correlation between Trp catabolism intrauterine has never been investigated, we aimed to assess co-expression IDO, TDO placenta. We studied plasma levels its catabolite kinurenine (kyn), their with placental IDO expression. Maternal tissue samples (from maternal side) were obtained from pregnancies after vaginal delivery. Placental Ang(1-7), expression was assessed by immunofluorescence (n=20). Plasma kyn measured ELISA (n=25). The different areas placenta compared univariate multivariate analyses. Statistical analyses performed. percentage cells expressing reported Tab. 1; co-expressed 47%, 46% 41% total side, side villi, respectively. A strong found TDO+ IDO+ villi (Pearson 0.68 0.86, respectively, p< 0.01). Of cells, 83% 69% 36% decidua basalis expressed Ang1-7+ (p< 0.001). Mean Kyn 597.2 ng/ml 8.3 μg/ml, Kyn/Trp ratio 0.08, it not correlated basalis. Ang(1-7) part complex tolerogenic signalling network helps create favourable niche embryonic implantation development.