Placental Gene Expression in Response to Histamine and Oxygen

Maternal Blood histamine levels are tightly controlled in normal pregnancy. However, in specific complications of human pregnancy such as pre-eclampsia the levels of both placental and maternal blood histamine increase. Increasing blood histamine levels nonetheless, have been associated with oxidative stress, endothelial dysfunction, abnormal tissue growth, and Th1/TH2 imbalance, which are also linked to pre-eclampsia. Little is known of the molecular responses in the placenta to the prolonged exposure to increasing histamine levels in the presence of changing oxygen concentrations. We used microarray to detail the global programme of placental gene expression in response to histamine and oxygen and identified distinct classes of regulated genes underlying the molecular functions of histamine in the placenta. Term (weeks 38 -40) placental micro explants from normal singleton pregnancies delivery by Elective Caesarean Sections were incubated in 8% (PL 8%) or 20% (PL 20%) oxygen for 6 days with (PL 8%-Treat or PL 20%-Treat) or without (PL 8%-Con or PL 20%-Con) histamine and aminoquanidine.