Interleukin-10 regulates arterial pressure in early primate pregnancy☆

Abstract Objectives In pregnancy, the placental contribution of cytokines to maternal immunosuppression has been established, however their role in normal maternal blood pressure regulation has not been identified. We investigate the contribution of interleukin-10 (IL-10) and tumor necrosis factor-α (TNF-α) to the vasodilation of early pregnancy in non-human primates. We also sequenced the IL-10 baboon gene and compared it with humans. Methods The effect of four different treatments, administered sequentially (semi-random-design) on resting 18 h, night time, or hourly mean arterial pressure (MAP) and heart rate (HR) were measured using telemetry. An anti-human IL-10 monoclonal antibody (MAb, 1 mg, n  = 7), anti-TNF-α antibody ( n  = 3), a combination of anti-IL-10 and anti-TNF-α antibodies ( n  = 5) or saline ( n  = 3) control were administered intravenously to baboons in early pregnancy. Plasma and placental IL-10 concentration was measured before and after injection in all animals. Results Anti-human IL-10 MAb caused a significant increase in MAP of 2.6 ± 0.5 mmHg over the 18-h period ( p Conclusions IL-10 was shown to regulate the vasodilation of early pregnancy in Papio hamadryas . This partial role of IL-10 in the early BP response of primate pregnancy may be relevant to pathophysiological states of human pregnancy such as preeclampsia.