CHANGES IN BLOOD-ALCOHOL LEVELS AS A FUNCTION OF ALCOHOL CONCENTRATION AND REPEATED ALCOHOL EXPOSURE IN ADULT FEMALE RATS - POTENTIAL RISK-FACTORS FOR ALCOHOL-INDUCED FETAL BRAIN INJURY

Fetal alcohol syndrome and alcohol-related birth defects are the result of heavy maternal alcohol consumption during gestation. The magnitude of deficit manifested by the offspring is invariably a consequence of several risk factors that may result in high peak blood alcohol concentrations (BACs), such as the duration, timing, or pattern of alcohol consumption. In addition, the alcohol content of the consumed beverage may play a role in determining offspring developmental consequences. Because higher BACs are positively correlated with risk and severity of brain injury early in postnatal life, initially it was important to determine how BAC is influenced by alcohol concentration and whether that influence is constant over repeated alcohol treatments. Groups of female Sprague-Dawley rats received daily intragastric intubations of 5 g/kg alcohol in one of several concentrations: 45% (v/v), 30% (v/v), 22.5% (v/v), or 15% (v/v) for a duration of 18 consecutive days. Blood samples were taken at various times postintubation on days 3, 8, 13, and 18 of treatment, and analyzed by headspace gas chromatography. Multivariate analyses of peak BAG, average BAG, and time to reach peak BAC revealed some noteworthy results. First, peak BAC and average BAC were significantly lower in the 45% group, compared with the other concentration groups, whereas this group also took a longer time to reach peak BAC than the other three groups. Second, peak BAC and average BAC were higher on the last day of treatment than any of the other treatment days. These results suggest that alcohol concentration and repeated alcohol exposure can influence BAC and, as such, are important risk factors to be considered in the appraisal of alcohol-induced fetal brain injuries.