PS30. Gender difference in stress responses as examined by TSPO (Translocator Protein 18 kDa), cortisol and STAI (State-Trait Anxiety Inventory) in normal human subjects.

Abstract

Abstract It has been shown that TSPO (Translocator Protein 18kDa, formerly known as the peripheral-type benzodiazepine receptor), which is involved in the production of steroid hormones, is increased under acute stress and decreased under chronic stressful condition. In our previous studies, expression of TSPO on platelets was significantly correlated with trait anxiety rather than state anxiety in normal human subjects, possibly reflecting an individual’s sensitivity to stress. Males were more sensitive than females in these stress responses. It remains to be seen, however, how platelet TSPO densities, anxiety scores and stress hormones, such as cortisol, are correlated each other. In the present study, we examined these relationships in normal human subjects (88 males, 74 females, age 20–80), focusing on gender difference. In normal subjects, plasma cortisol levels were significantly (p<0.05) correlated with state anxiety scores in males, and similarly correlated in females, whereas they were not correlated with trait anxiety scores (as examined by STAI). In contrast, platelet TSPO showed a tendency of inverse correlation with plasma cortisol in males, whereas no correlation was seen in females Changes in the expression of TSPO were not accompanied by changes in cortisol. In conclusion, alterations in the expression of TSPO seem to be a sensitive indicator of stress.