Fluoxetine induces vasopressin and oxytocin abnormalities in food-restricted rats given voluntary exercise: relationship to anorexia nervosa

Brain Res. 1993 May 28;612(1-2):180-9. doi: 10.1016/0006-8993(93)91659-g.


Anorexia nervosa is associated with vasopressin, oxytocin and serotonin abnormalities. Because of the relationship between exercise and anorexia nervosa, we explored the weight-loss syndrome produced by wheel running in food-deprived rats. Its effects on regional vasopressin and oxytocin concentrations were determined under basal conditions and following systemic fluoxetine. Weight-matched, exercised and unexercised rats served as controls. Fluoxetine caused abnormalities in suprachiasmatic vasopressin and dynorphin A content and in thymus oxytocin content that did not occur in weight-matched or exercised controls. No syndrome-specific anomalies occurred in the hypothalamo-neurohypophysial system or dorsal vagal complex (DVC). However, weight reduction and fluoxetine increased circulating vasopressin; moderate exercise caused fluoxetine-induced elevations in posterior pituitary vasopressin and oxytocin; and, unlike the other groups, fluoxetine increased DVC oxytocin in freely fed unexercised rats. It was concluded that syndrome-specific vasopressin and oxytocin abnormalities occur that are not secondary to weight loss or moderate exercise; that weight loss or fluoxetine increases circulating vasopressin; that moderate exercise alters neurohypophysial vasopressin and oxytocin content; and that weight loss or exercise inhibits a fluoxetine-stimulated increase in DVC oxytocin. Finally, it was argued that the fluoxetine abnormalities indicate possible serotonin dysfunction in the syndrome.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Anorexia Nervosa / metabolism*
  • Behavior, Animal / drug effects
  • Body Weight / drug effects
  • Body Weight / physiology
  • Dynorphins / metabolism
  • Eating*
  • Fluoxetine / pharmacology*
  • Male
  • Oxytocin / metabolism*
  • Physical Conditioning, Animal*
  • Rats
  • Rats, Sprague-Dawley
  • Suprachiasmatic Nucleus / physiology
  • Supraoptic Nucleus / physiology
  • Vagus Nerve / physiology
  • Vasopressins / metabolism*


  • Fluoxetine
  • Vasopressins
  • Oxytocin
  • Dynorphins