These data suggest that reactive oxygen species (ROS) are critical for the early stages of the salt-dependent increases in blood pressure, and it is hypothesized that the female sex does not protect against hypertension in the DβH-ETB:ETBsl/sl model similar to other models of hypertension due to increased circulating ET-1 and superoxide production (Sullivan et al., 2006). This evidence concerns the gene EDN1 and hypertensive disorder.