TIME KINETICS OF THE ENDOCRINE RESPONSE TO ACUTE PSYCHOLOGICAL STRESS

A first-time parachute jump was chosen as a model to evaluate the endo crine response to acute psychological stress. In 43 inexperienced tand em parachutists, blood was drawn continuously from 2 h before to 1 h a fter the jump and analyzed at 10-min intervals for plasma concentratio ns of epinephrine (E), norepinephrine (NE), cortisol, GH, PRL, and TSH . In addition, heart rate was recorded throughout the experiment. Ther e was a significant increase in heart rate and E concentrations during the jump itself. NE, cortisol, GH, PRL, and TSH peaked with a latency of 10-20 min. Apart from cortisol and TSH concentrations, which were still elevated Ih after the stress event, plasma levels of the other e ndocrine variables normalized within 1 h following the jump. Statistic ally significant cross-correlations could be observed between E and NE (r = 0.60, no time lag) and between E and PRL (r = 0.58, 10-min time lag) only. Even in a very homogenous group of subjects and under well- controlled conditions, endocrine responses to acute psychological stre ss show considerable variations.