Red blood cell in preeclampsia: attenuated nitric oxide generation and enhanced reactive oxygen species formation and eryptosis.

Preeclampsia (PE) pathogenesis is strongly related to diminished nitric oxide (NO) bioavailability and enhanced oxidative stress. Emerging evidence suggests that red blood cells (RBCs) eNOS enzyme contributes to systemic NO bioavailability by its ability of both NO and ROS generation. We aimed to investigate RBC eNOS enzyme activity, NO and ROS generation capacity, eryptosis index and aggregation levels in preeclamptic and uncomplicated pregnant women. Fifty-eight PE patients and 36 healthy pregnant women were included to the investigation. RBC eNOS enzyme activity, intracellular NO, calcium and ROS concentrations and eryptosis levels were determined via flow cytometric methods. RBC deformability and aggregation were measured via LORRCA. Intracellular NO and phosphorylated RBC eNOS levels decreased in PE group compared to healthy pregnant group (p < 0.05, p < 0.001 respectively). Intracellular ROS and calcium levels, eryptosis values and aggregation indexes in the PE group were significantly higher than healthy pregnant group (p < 0.05, p < 0.01, p < 0.05, p < 0.05 respectively). Our results demonstrate for the first time that RBC produce lower NO and higher ROS under PE conditions. Further, RBC of PE patients were more prone to eryptosis and aggregation compared to control group. Our results suggest that, in addition to endothelial cells, RBC also contribute to decreased plasma NO bioavailability via producing less NO and high ROS in PE. Considering increased tendency to eryptosis and aggregation, RBC seem to play role in haemodynamic changes of PE pathogenesis.