Effect of p-chlorophenylalanine on diazepam withdrawal signs in rats.

The effect of p-chlorophenylalanine (PCPA), a specific serotonin (5-HT) depleter, on diazepam withdrawal signs was studied. Rats were made dependent on diazepam by the chronic administration of this drug in the diet. At the time of diazepam withdrawal, the animals were treated with PCPA (200 mg/kg, IP) or the corresponding vehicle (control). After diazepam withdrawal, the maximal body weight losses of control and PCPA-treated animals were 4.1% and 9.0%, respectively. In naive animals, PCPA did not cause any change in body weight. These results suggest that depletion of central 5-HT by PCPA may potentiate the severity of diazepam withdrawal signs.