EFFECT OF RESTRAINT STRESS ON FEEDING-BEHAVIOR OF RATS

The expression of appetite reflects the complex functioning of a psych obiological system organized in different levels closely related to ea ch other, in which emotional changes can influence feeding behavior. B enzodiazepines are widely used as anxiolytics and can change behaviors caused by stress. The aim of the present study was to verify the feed ing behavior of rats, submitted or not to fasting, after acute and chr onic restraint stress. We also evaluated the response to the ingestion of sweet food of chronically restrained animals after the administrat ion of diazepam. Male adult Wistar rats were exposed to restraint 1 h/ day for 50 days in the chronic model. In the acute model, there was a single exposure. Four hours after the stress, the animals were placed in a lightened area in the presence of 10 pellets of sa eet food (Froo t Loops(TM)). The number of ingested Froot Loops(TM) was measured duri ng a period of 3 min, in the presence or absence of fasting. The group s acutely stressed showed ingestion similar to that of the control gro up, whether they had been fasted or not. The chronically stressed anim als showed increased ingestion of sweet food. Diazepam given 60 min be fore the test session of the stressed rats reduced the ingestion of th ese animals to control levels. Thus, the chronic stress increases appe tite for sweet food, independently of hunger, and diazepam is able to reverse this behavior. (C) 1997 Elsevier Science Inc.