FIG. 4.

Mechanisms of ROS action on the HPA axis. The effects of ROS on the HPA axis might be explained as follows: SLS may directly alter the physiological functioning of the HPA axis, leading to an increased production of ROS by mitochondria and NADPH oxidase. This elevation in oxidative stress affects the translocation of the GR, induces an increase in glutamate release leading to glutamate excitotoxicity, and alters RNA synthesis and stability. Alternatively, the alteration of the physiological functioning of the HPA axis might be observed later, as a consequence of the altered GR translocation, glutamate excitotoxicity, and impaired RNA synthesis. GR, glucocorticoid receptor.