Perinatal protein deprivation enhances the anticonflict effect measured after chronic ethanol administration in adult rats.

The anticonflict effects of ethanol, diazepam and pentobarbital were evaluated in adult rats fed a low protein diet during the perinatal period in the plus-maze test, after single injections and following chronic ethanol administration (1 g.kg-1.d-1 for 30 d). Reactivity to the anticonflict effect of these drugs was similar in control and protein-deprived rats after acute treatment. After chronic ethanol administration, control rats showed tolerance to ethanol and cross-tolerance (i.e., lower reactivity) to the anxiolytic effect of diazepam and pentobarbital. Conversely, protein-deprived rats showed greater reactivity to ethanol and lack of cross-tolerance to diazepam and pentobarbital following chronic ethanol treatment. A significantly greater density of cortical gamma-aminobutyric acid receptors subtype A (GABA-A) was detected in protein-deprived rats after chronic ethanol administration compared with the density after chronic saline treatment, whereas no differences were observed in nourished controls. This suggests that the greater anxiolytic activity detected in protein-deprived rats may correlate with higher GABA-A receptor density.