NOX4 and preeclampsia: The major findings of the present study were: (1) The rat model of preeclampsia by administrating DOCA and saline showed an increase in MAP, HR, and the content of norepinephrine in the 24 h urine; (2) the ROS level in the RVLM in preeclampsia rats was significantly increased; (3) the protein expression of NOX4 in the RVLM was up-regulated in preeclampsia rats; (4) microinjection of Tempol into the RVLM significantly decreased BP, HR, and RSNA in preeclampsia rats.