Effects of bromocriptine on the voluntary consumption of ethanol, water, and solid food by UChA and UChB rats

The effect of bromocriptine (stimulant of dopaminergic D2 receptors) on the daily consumption of 10% v/v ethanol solution, distilled water, and solid food, under free-choice conditions, was measured in nine genetically low (UChA) and six high ethanol consumer (UChB) adult female rats. Animals were housed in individual cages and maintained at room temperature of 23 +/- 1 degree C and with 12/12 h dark/light rhythm. The consumption of ethanol solution, water, and solid food was measured in pretreatment, treatment, and posttreatment periods of 3 days (Tuesday through Thursday) of 3 consecutive weeks. During the treatment period rats received daily a single oral dose of 8 mg of bromocriptine mesylate (Sandoz) suspended in 1 ml of water per kg of body weight. Data analysis was performed with a method previously reported, which allows to recognize specific effect of ethanol intake, depurated from the effects on calories and/or water consumption. Results showed that all UChB rats decreased significantly and specifically the consumption of ethanol solution during the treatment period compared to the pretreatment period (mean: -58 +/- 15%) and recovered the pretreatment consumption in the posttreatment period, without significant changes in the consumption of food and/or total water. The only significant change observed in UChA rats was a decrease of the consumption of solid food (mean: -15 +/- 5%). Results are consistent with the idea that a dopaminergic D2 synapsis participates in the neural network responsible for satiation with ethanol.