Suppression of hypothalmic-pituitary-adrenal axis responses to stress in lactating women Academic Article uri icon


MeSH Major

  • Exercise Test
  • Hormones
  • Hypothalamo-Hypophyseal System
  • Lactation
  • Pituitary-Adrenal System
  • Postpartum Period
  • Stress, Physiological


  • In the rat, lactation suppresses a variety of physiological responses to stress. We investigated whether stress-responsive neurohormonal systems are also restrained during breast feeding in humans. We chose treadmill exercise as a stressor because this stimulus produces an exercise intensity-dependent activation of the hypothalamic-pituitary-adrenal axis and the sympathomedullary system that is independent of differences in physical conditioning among subjects. Ten lactating and ten nonlactating women who were between 7 and 18 weeks postpartum performed 20 min of graded treadmill exercise. The final 5 min of exercise was set to elicit 90% of the maximal oxygen uptake of each subject. Plasma ACTH, cortisol, and glucose responses to exercise were significantly attenuated in lactating women (P < 0.001, P < 0.05, and P < 0.001, respectively). Basal norepinephrine levels were also reduced in lactating women (P < 0.05). These results indicate that stress-responsive neurohormonal systems are restrained in lactating women.

publication date

  • January 1995



  • Academic Article



  • eng

PubMed ID

  • 7559880

Additional Document Info

start page

  • 2954

end page

  • 9


  • 80


  • 10