Age- and ethanol concentration-dependent effects of acute binge drinking in the HIV-1 transgenic rat.

BACKGROUND: Binge drinking is common in young people. Alcoholic beverages vary significantly in their ethanol (EtOH) concentration (alcohol by volume). We previously showed EtOH concentration-dependent activation of the hypothalamic supraoptic nucleus. In the HIV-infected population, incidence of alcohol abuse is close to 50%. We found age-dependent expression of HIV-1 viral proteins in the HIV-1 transgenic (HIV-1Tg) rat. Thus, we hypothesized that there are age- and EtOH concentration-dependent effects of binge drinking in HIV-1-positive individuals.

METHODS: Blood ethanol concentration was measured in adult F344 rats after gavage (i.g.) administration of water, 20% EtOH, or 52% EtOH. We also compared expression of the HIV-1 viral protein Tat in the brain, spleen, and liver of adult and adolescent HIV-1Tg rats following binge i.g. administration of water, 20% EtOH, or 52% EtOH for 3 days (4.8 g/kg/d) using absolute quantitative real-time reverse transcription-polymerase chain reaction. In a parallel study, we assessed age-dependent motor function in the HIV-1Tg rats 1 day after exposure to 20% EtOH using the open-field test.

RESULTS: Blood ethanol concentration was significantly higher in the 52% EtOH-treated F344 rats compared to the 20% EtOH animals at 90 minutes posttreatment. In the adult HIV-1Tg rats, HIV-1 Tat expression (copies per microgram of total RNA) was significantly increased in the brain, liver, and spleen of the 52% EtOH group, but not in the 20% EtOH group. However, in the adolescent animals, HIV-1 Tat expression in the 52% EtOH group was increased in the brain and liver, but not in the spleen. A significant reduction in locomotor activity occurred in 20% EtOH-treated adult HIV-1Tg rats compared to the water control, although no difference was observed in the adolescent HIV-1Tg animals.

CONCLUSIONS: Our data indicate that binge alcohol drinking can have age- and EtOH concentration-dependent effects in the presence of HIV-1 infection.