ETHANOL AND NICOTINE CONSUMPTION AND PREFERENCE IN TRANSGENIC MICE OVEREXPRESSING THE BOVINE GROWTH-HORMONE GENE

Transgenic mice overexpressing the phosphoenolpyruvate carboxykinase/b ovine growth hormone (PEPCK/ bGH) hybrid gene and normal (nontransgeni c) littermate controls (10 males + 10 females/group) were given access to tapwater and an ascending series of concentrations of ethanol (1.0 -22.0%), then a similar ascending series of concentrations of nicotine (1.0-40.0 mu g/ml), in a two-bottle choice test. Male transgenic mice consumed more and exhibited greater preferences for ethanol and nicot ine than control males; transgenic females consumed less and showed lo wer preferences for ethanol, but not nicotine, than control females. T hese results suggest that chronic exposure to high levels of bGH may m odulate the rewarding effects of ethanol and nicotine in mice in a gen der-specific fashion.