Prolactin in response to acute psychosocial stress in healthy men and women

Abstract

Background: Serum levels of the anterior pituitary hormone prolactin have been reported to increase in response to different types of psychological stressors in humans. However, experimental laboratory stress studies investigating the acute response of prolactin to psychological stress show inconsistent results as increased, as well as decreased or unchanged levels of prolactin have been reported.

Objective: The aim of this study was to investigate the effect of acute psychosocial stress on serum concentrations of prolactin in healthy men and women and possible sex differences.

Method: Thirty men and 15 women (age 30-50 years) underwent Trier Social Stress Test (TSST), a tool for investigating psychobiological stress responses in a laboratory setting. Blood samples were collected before and directly after the stress test and after 30 min of recovery.

Results: We observed significantly elevated prolactin levels - along with significantly increased plasma adrenocorticotropic hormone (ACTH), serum cortisol, heart rate, systolic blood pressure (SBP), and diastolic blood pressure (DBP) - in response to the stressor. The prolactin response pattern did not differ between men and women, but there was some indication that women might have higher magnitude of response. Large individual differences regarding the magnitude of response were seen in general. The magnitude of the prolactin response was significantly related to the magnitude of the response of the hypothalamic-pituitary-adrenal (HPA) axis and, to some extent, the cardiovascular responses, indicating that individual differences in prolactin response in healthy men and women are dependent on the general physiological stress activation. In women, the magnitude of response was also related to estradiol level.

Conclusion: Prolactin does increase in response to psychosocial stress, however, with large individual variation in magnitude of response. The pattern of prolactin response does not differ between men and women. However, there was some indication that women might have higher magnitude of increase than men, and that the magnitude of response in women was dependent on estradiol levels, and this needs to be further studied.