Peripheral oxytocin administration decreases the food intake and compulsive-like behavior in male rats in an animal model of binge-type eating.

Hormone oxytocin is implicated in the control of food intake and energy balance. Experimental evidence indicates that oxytocin reduces carbohydrate intake, motivation and seeking for palatable foods. We recently showed that intermittent intake of palatable food promotes binge-type eating in rats. However, whether oxytocin can reduce the binge size has not been shown. Moreover, the behavioral mechanism by which oxytocin controls the intake of palatable food has not been described yet. Here, male Wistar rats were intermittently provided with a palatable food high in sugar over a period of four weeks. Rats increased the consumption of the palatable diet and gradually reached the binge criteria. After that, we measured food intake and parameters of the Behavioral Satiety Sequence analysis (BSS) in the home-cage following oxytocin administration (1 mg/kg, i.p.). Then, compulsive-like eating was measured following the same dose of oxytocin. Oxytocin administration decreased the binge for palatable food. Behavioral analysis revealed that oxytocin increased time resting and decreased the initial food consumption. This occasioned the disruption of the BSS structure (orderly transition from eating to sleeping) and promoted a late onset of the satiety. Moreover, oxytocin administration increased the latency to eat and decreased the food intake in the aversive/anxiogenic open field. Our data suggested that oxytocin administration reduced the binge for palatable food, restructuring the natural development of satiety and decreasing the signs of compulsive-like eating behavior.