An animal model of bulimia nervosa: opioid sensitivity to fasting episodes.

A group of female rats was deprived and maintained at 75-80% of body weight at three different times during development. Following recovery to normal weight, food intake was measured with and without butorphanol tartrate, a kappa-sigma agonist, 8 mg/kg SC. Animals with a history of deprivation (DEP) showed an increase in postrecovery feeding when they were tested at normal body weight and not food deprived. More importantly, butorphanol prolonged food intake in the 3-h eating test only in the rats with a developmental history of food restriction. A developmental history of fasting in eating disorders may trigger changes in opiate systems that result in atypical feeding behavior in the adult.