Fluoxetine induces vasopressin and oxytocin abnormalities in food-restricted rats given voluntary exercise: relationship to anorexia nervosa.
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.
Aravich
P F
PF
Department of Anatomy and Neurobiology, Eastern Virginia Medical School, Norfolk 23501.
Rieg
T S
TS
Ahmed
I
I
Lauterio
T J
TJ
D000818:Animals; D000856:Anorexia Nervosa / Q000378:metabolism*; D001522:Behavior, Animal / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D004399:Dynorphins / Q000378:metabolism; D004435:Eating; D005473:Fluoxetine / Q000494:pharmacology*; D008297:Male; D010121:Oxytocin / Q000378:metabolism*; D010805:Physical Conditioning, Animal; D051381:Rats; D017207:Rats, Sprague-Dawley; D013493:Suprachiasmatic Nucleus / Q000502:physiology; D013495:Supraoptic Nucleus / Q000502:physiology; D014630:Vagus Nerve / Q000502:physiology; D014667:Vasopressins / Q000378:metabolism*
D005473:Fluoxetine; D014667:Vasopressins; D010121:Oxytocin; D004399:Dynorphins