Estradiol level of male rat is correlated with depression and anxiety after traumatic stress

Abstract

Post-traumatic stress disorder (PTSD) is a complex syndrome that is defined by individual exposed to intense, life-threatening trauma thereby leading to physical and psychological abnormalities. They further develop additional symptoms including persistent anxiety, exaggerated startle, cognitive impairments, and diminished extinction of fear. Most of the previous studies focused on brain and neurophysiology, but PTSD affects the whole body. Therefore, we wanted to concentrate more on the effects on sex hormones using rats. Testosterone and estradiol are major sex hormones in male and female which are well known to participate in not only reproduction but also brain function and behaviors. Two behavioral tests, open field test and tail suspension test, were used to determine whether animals have PTSD-like symptoms. At the same time, serum samples were collected for sex hormone analysis. We investigated the influences of traumatic stress and then tried to find out the correlations of behaviors and hormones. In results, 22% of rats were affected by stress based on the behavioral tests and grouped as PTSD-like. These rats showed enhanced anxiety and depression behaviors. In serum samples from the PTSD-like group, only estradiol levels in male after stress are significant higher than the control or stressed but no symptom groups. Testosterone level showed no difference after stress both in male and female. We also observed that only estradiol level in male correlates with PTSD-like behaviors. It indicates that estradiol levels in male just after traumatic stress might be an indicator for PTSD-like symptoms.

Keywords

• Posttraumatic stress disorder
• sex-hormone
• estradiol
• depress
• anxiety