MALE FEMALE COMPARISON OF MORPHINE EFFECT ON FOOD-INTAKE - RELATION TO ANOREXIA-NERVOSA/

We have proposed that endogenous opioids play a critical role in the e tiology of anorexia nervosa by mediating an auto-addiction. A biologic al predisposition may result from an atypical endogenous opioid system . Morphine activation of the system increases food intake in most spec ies, including normal humans and rats, but decreases food intake in mi ce. The atypical opioid system in mice may be representative of that i n anorexia nervosa patients, causing the biological predisposition. An orexia nervosa is 10 times more prevalent in females than males. In th e context of this auto-addiction opioid model, it was interesting to d etermine if the effects of morphine on food intake were markedly diffe rent between the two sexes. Full dose-response curves were done of the effects of morphine on food intake in males and females in both rats and mice, representing the typical and atypical responses, respectivel y. Differences between the sexes were not found to explain the marked prevalence of anorexia nervosa for females. The marked preference is p robably at some other step.