naloxone and Bulimia

To test the hypothesis that endogenous opiate peptides selectively influence hedonic response to sweet and high-fat foods, the opiate antagonist naloxone, opiate agonist butorphanol, and a saline placebo were administered by intravenous infusion to 16 obese and 25 normal-weight women. Twenty of the women (10 obese, 10 lean) fulfilled DSM-III-R diagnostic criteria for bulimia nervosa, as determined by psychiatric interview. During drug infusion the women tasted and rated 20 sweetened dairy products and were presented with eight snack foods of varying sugar and fat content. Naloxone suppressed hedonic responses in all subject groups and suppressed the consumption of sweet and high-fat foods in binge eaters, but not in nonbingers. Food intakes of obese women were not affected by naloxone. Butorphanol had no effect on either hedonic response or on food consumption in any group. Although opiate blockade is not a viable strategy for weight reduction in the treatment of obesity, it may be useful in the clinical management of the binge-eating disorder.

Topics: Adult; Bulimia; Butorphanol; Dietary Carbohydrates; Dietary Fats; Double-Blind Method; Eating; Energy Intake; Female; Food Preferences; Humans; Infusions, Intravenous; Naloxone; Obesity; Taste

Preferences and cravings for sweet high-fat foods observed among obese and bulimic patients may involve the endogenous opioid peptide system. The opioid antagonist naloxone, opioid agonist butorphanol, and saline placebo were administered by intravenous infusion to 14 female binge eaters and 12 normal-weight controls. Eight of the binge eaters were obese. During infusion, the subjects tasted 20 sugar/fat mixtures and were allowed to select and consume snack foods of varying sugar and fat content. Naloxone reduced taste preferences relative to baseline in both binge eaters and controls. Total caloric intake from snacks was significantly reduced by naloxone in binge eaters but not in controls. This reduction was most pronounced for sweet high-fat foods such as cookies or chocolate. No consistent effects on taste preferences or food intakes were observed with butorphanol. Endogenous opioid peptides may be involved in mediating taste responses and preferences for palatable foods, notably those rich in sugar and fat.

Topics: Adolescent; Adult; Body Weight; Bulimia; Butorphanol; Dietary Carbohydrates; Dietary Fats; Endorphins; Energy Intake; Female; Food Preferences; Humans; Naloxone; Receptors, Opioid; Satiety Response; Taste

We undertook a study to see if putative anorectic agents could attenuate binge eating episodes in bulimic patients. Bolus intravenous administration, followed by continuous intravenous infusion of naloxone, resulted in a significant decrease in the amount of food consumed during binge-eating episodes, whereas bolus followed by continuous intravenous infusion of CCK-8 failed to significantly suppress binge eating behavior. These results suggest that the endogenous opioid system is involved in the maintenance of binge eating behavior in patients with bulimia.

Topics: Adult; Appetite Depressants; Bulimia; Clinical Trials as Topic; Female; Humans; Infusions, Intravenous; Injections, Intravenous; Naloxone; Sincalide

Previous studies suggest that binge eating sugar leads to behavioral and neurochemical changes similar to those seen with drug addiction, including signs of opiate-like withdrawal. Studies are emerging that show multiple neurochemical and behavioral indices of addiction when animals overeat a fat-rich diet. The goal of the present study was to utilize liquid and solid diets high in sugar and fat content to determine whether opiate-like withdrawal is seen after binge consumption of these diets in Sprague-Dawley rats. Control groups were given ad libitum access to the sweet-fat food or standard chow. All rats were then given a battery of tests to measure signs of opiate-like withdrawal, which included somatic signs of distress, elevated plus-maze anxiety, and locomotor hypoactivity. Neither naloxone-precipitated (3 mg/kg) nor deprivation-induced withdrawal was observed in rats that were maintained on a nutritionally complete pelleted sweet-fat diet or a sweet, high-fat diet supplemented with standard rodent chow. Naloxone-precipitated withdrawal was also not seen in rats fed a liquid sweet-fat food. Further, body weight reduction to 85%, which is known to potentiate the reinforcing effects of substances of abuse, did not affect naloxone-precipitated signs of opiate-like withdrawal. Thus, unlike previous findings reported regarding rats with binge access to a sucrose solution, rats that binge eat sweet-fat combinations do not show signs of opiate-like withdrawal under the conditions tested. These data support the idea that excessive consumption of different nutrients can induce behaviors associated with addiction in different ways, and that the behaviors that could characterize "food addiction" may be subtyped based on the nutritional composition of the food consumed.

Topics: Analysis of Variance; Animals; Behavior, Addictive; Body Weight; Bulimia; Diet, High-Fat; Disease Models, Animal; Eating; Exploratory Behavior; Feeding Behavior; Food; Male; Maze Learning; Motor Activity; Naloxone; Narcotic Antagonists; Rats; Rats, Sprague-Dawley; Substance Withdrawal Syndrome; Time Factors

The authors developed an animal model of binge eating where history of caloric restriction with footshock stress (R + S) causes rats to consume twice the normal amount of palatable food. The authors tested the hypothesis that binge eating is mediated by changes in opioid control of feeding by comparing rats' anorectic and orexigenic responses to naloxone and butorphanol, respectively, and by testing the ability of butorphanol to elicit binge eating of chow when palatable food was absent. Mu/kappa opioid-receptor blockade and activation had exaggerated responses in the R + S rats with naloxone suppressing binge eating to control levels, and although butorphanol did not trigger chow binge eating, it enhanced binge eating of palatable food. These responses in sated normal-weight rats strengthen evidence that reward, over metabolic need, drives binge eating.

Topics: Analgesics, Opioid; Analysis of Variance; Animals; Behavior, Animal; Body Weight; Bulimia; Butorphanol; Caloric Restriction; Disease Models, Animal; Electroshock; Energy Intake; Feeding Behavior; Female; Food Preferences; Naloxone; Narcotic Antagonists; Narcotics; Rats; Rats, Sprague-Dawley; Time Factors

The present study was undertaken in order to establish whether alterations in the endogenous opioid control of luteinizing hormone (LH) and ACTH/cortisol secretion occur in bulimic women with normal body weight and normal menstrual cycles. For this purpose, the capability of the opioid antagonist naloxone (4 mg injected as an intravenous bolus at time 0, plus 10 mg infused over 2 hr) to increase the circulating levels of LH and cortisol was tested in nine bulimic women and in nine age- and weight-matched normal controls. All women were tested on the 22nd day of a normal menstrual cycle. Two days later, a control test with normal saline (NaCl 0.9%) instead of naloxone was performed. The basal levels of LH and cortisol were similar in the bulimic and normal subjects and were not modified by the administration of normal saline. In contrast, the administration of naloxone significantly increased plasma LH and cortisol levels in all subjects, with peak LH responses at 30 min and peak cortisol responses at 60 min. The naloxone-induced LH and cortisol increases were significantly higher in the bulimic women than in the normal controls. These data indicate the presence of an increased opioid inhibitory tone in the control of LH and ACTH/cortisol secretion in normal weight bulimic women with normal menstrual cycles.

Topics: Adult; Bulimia; Estradiol; Female; Humans; Hydrocortisone; Luteinizing Hormone; Naloxone

Topics: Bulimia; Double-Blind Method; Feeding Behavior; Female; Food Preferences; Humans; Naloxone; Placebos