Interaction between repeated restraint stress and concomitant midazolam administration on sweet food ingestion in rats

Emotional changes can influence feeding behavior. Previous studies have sho wn that chronically stressed animals present increased ingestion of sweet f ood, an effect reversed by a single dose of diazepam administered before re sting the animals. The aim of the present study was to evaluate the respons e of animals chronically treated with midazolam and/or submitted to repeate d restraint stress upon the ingestion of sweet food. Male adult Wistar rats were divided into two groups: controls and exposed to restraint 1 h/day, 5 days/week for 40 days. Both groups were subdivided into two other groups t reated or not with midazolam (0.06 mg/ml in their drinking water during the 40-day treatment). The animals were placed in a lighted area in the presen ce of 10 pellets of sweet food (Froot loops(R)). The number of ingested pel lets was measured during a period of 3 min, in the presence or absence of h ating. The group chronically treated with midazolam alone presented increas ed ingestion when compared to control animals (control group: 2.0 +/- 0.44 pellets and midazolam group: 3.60 +/- 0.57 pellets). The group submitted to restraint stress presented an increased ingestion compared to controls (co ntrol group: 2.0 +/- 0.44 pellets and stressed group: 4.18 +/- 0.58 pellets ). Chronically administered midazolam reduced the ingestion in stressed ani mals (stressed/water group: 4.18 +/- 0.58 pellets; stressed/midazolam group : 3.2 +/- 0.49 pellets). Thus, repeated stress increases appetite for sweet food independently of hunger and chronic administration of midazolam can d ecrease this behavioral effect.