Beta-endorphin, but not substance-P, is increased by acute stress in humans

Psychoneuroendocrinology. 1995;20(1):103-10. doi: 10.1016/0306-4530(94)00048-4.


The role of neuropeptides in the psychoneuroendocrinological stress response is largely unknown. In this study the effect of acute psychological stress on beta-endorphin and substance-P plasma concentrations was investigated and further the effect of different anxiety levels or control attributions on beta-endorphin or substance-P levels were determined. Blood samples were obtained from 47 inexperienced tandem-parachutists 2 h before, immediately after, and 1 h after a parachute jump and plasma concentrations of beta-endorphin and substance-P were analysed. Anxiety levels and control attributions were assessed by psychometric scales. Whereas substance-P concentrations seemed to be unaffected by the jump stress, there was a transient but significant increase in beta-endorphin levels immediately after jumping. However, subjects higher in state-anxiety at the point of jumping (exit) displayed higher substance-P values at all three time points compared to the "low-anxiety" jumpers. In addition, stress-induced beta-endorphin secretion was dependent on subjective control attributions.

MeSH terms

  • Adult
  • Anxiety / blood*
  • Anxiety / psychology
  • Arousal / physiology*
  • Aviation
  • Humans
  • Internal-External Control
  • Male
  • Personality Inventory
  • Stress, Psychological / blood
  • Stress, Psychological / complications*
  • Substance P / blood*
  • beta-Endorphin / blood*


  • Substance P
  • beta-Endorphin