Ethanol Exposure Increases Oxygen Consumption by Developing Cerebral Arteries in a Trimester-, Concentration- and Sex-Dependent Manner

Alcohol (ethanol; EtOH) intake affects one in ten pregnancies in the United States and is a leading cause of developmental defects collectively known as fetal alcohol spectrum disorders (FASDs). Cerebral circulation is a critical target of prenatal ethanol exposure (PEE), yet the target(s) involved remain poorly understood. In adult cerebral circulation, mitochondrial function is essential in regulating smooth muscle contractility, suggesting mitochondria as a potential target of alcohol in the developing cerebral arteries. In this study, pregnant C57BL/6J mice were administered ethanol (3, 4.5, 6, or 7 g/kg) during either the second trimester equivalent of human pregnancy (gestational days 9-19), or the third trimester equivalent during postnatal days 1-10. Maternal and progeny blood ethanol concentrations, progeny brain weight, cerebral artery oxygen consumption, and corticosterone levels were measured. At lower ethanol concentrations (3 g and 4.5 g/kg), no significant alterations in fetal cerebral artery mitochondrial function were detected. In contrast, heavy maternal ethanol exposure (6 g/kg) significantly increased mitochondrial respiratory parameters in developing cerebral arteries during the third trimester equivalent of human pregnancy. Sex-specific dimorphism was also observed at this developmental stage. Corticosterone was not elevated in fetuses and pups. In summary, our findings demonstrate developmental stage- and sex-dependent vulnerabilities of cerebrovascular oxygen consumption to ethanol exposure.