Histamine stimulates interleukin-6 production through histamine H1 receptors in human amnion cells.

Background/aims: Previous studies have stated that maternal allergic diseases are associated with increased risk of preterm labor/delivery, but the underlying mechanisms remain unclear. This study tested the hypothesis that histamine induces interleukin (IL)-6 production in amnion cells.

Methods: Using cultured human amnion cells, we examined expression of histamine receptors and effects of histamine on IL-6 production.

Angiotensin II mimics the hypoxic effect on regulating trophoblast proliferation and differentiation in human placental explant cultures.

Regulation of cytotrophoblast differentiation toward extravillous trophoblasts (EVTs) is critical for establishing successful pregnancy. Previous studies have focused primarily on the factors promoting the differentiation, while inhibitory regulators except hypoxia have been less documented. In this study, to test our hypothesis that angiotensin II (Ang II) would inhibit EVT differentiation, we investigated the effects of Ang II on trophoblast outgrowth and the expression of molecules associated with the proliferation and invasion of trophoblasts using human first trimester villous explant cultures.