Effect of Fetal Ethanol Exposure on the In Vitro Release of Growth Hormone, Somatostatin and Growth Hormone-Releasing Factor Induced by Clonidine and Growth Hormone Feedback in Male and Female Rats

Dihydromyricetin prevents fetal alcohol exposure-induced behavioral and physiological deficits: the roles of GABAA receptors in adolescence

Fetal alcohol exposure (FAE) can lead to a variety of behavioral and physiological disturbances later in life. Understanding how alcohol (ethanol, EtOH) affects fetal brain development is essential to guide the development of better therapeutics for FAE. One of EtOH's many pharmacological targets is the γ-aminobutyric acid type A receptor (GABAAR), which plays a prominent role in early brain development. Acute EtOH potentiates inhibitory currents carried by certain GABAAR subtypes, whereas chronic EtOH leads to persistent alterations in GABAAR subunit composition, localization and function. We recently introduced a flavonoid compound, dihydromyricetin (DHM), which selectively antagonizes EtOH's intoxicating effects in vivo and in vitro at enhancing GABAAR function as a candidate for alcohol abuse pharmacotherapy. Here, we studied the effect of FAE on physiology, behavior and GABAAR function of early adolescent rats and tested the utility of DHM as a preventative treatment for FAE-induced disturbances. Gavage administration of EtOH (1.5, 2.5, or 5.0 g/kg) to rat dams on day 5, 8, 10, 12, and 15 of pregnancy dose-dependently reduced female/male offspring ratios (largely through decreased numbers of female offspring) and offspring body weights. FAE (2.5 g/kg) rats tested on postnatal days (P) 25-32 also exhibited increased anxiety and reduced pentylenetetrazol (PTZ)-induced seizure threshold. Patch-clamp recordings from dentate gyrus granule cells (DGCs) in hippocampal slices from FAE (2.5 g/kg) rats at P25-35 revealed reduced sensitivity of GABAergic miniature inhibitory postsynaptic currents (mIPSCs) and tonic current (Itonic) to potentiation by zolpidem (0.3 μM). Interestingly, potentiation of mIPSCs by gaboxadol increased, while potentiation of Itonic decreased in DGCs from FAE rats. Co-administration of EtOH (1.5 or 2.5 g/kg) with DHM (1.0 mg/kg) in pregnant dams prevented all of the behavioral, physiological, and pharmacological alterations observed in FAE offspring. DHM administration alone in pregnant rats had no adverse effect on litter size, progeny weight, anxiety level, PTZ seizure threshold, or DGC GABAAR function. Our results indicate that FAE induces long-lasting alterations in physiology, behavior, and hippocampal GABAAR function and that these deficits are prevented by DHM co-treatment of EtOH-exposed dams. The absence of adverse side effects and the ability of DHM to prevent FAE consequences suggest that DHM is an attractive candidate for development as a treatment for prevention of fetal alcohol spectrum disorders.

Effect of ethanol intake during lactation on male and female pups' liver and brain metabolism during the suckling-weaning transition period

In rats, a high degree of brain development and myelination occurs during the first 15 days after birth. Ethanol intake by lactating rats modified 12 day-old pups' brain development and metabolism. The aim of the present study was to evaluate the effect of maternal ethanol ingestion during lactation on prepubertal (24-day-old) pups' brain and liver metabolism. Lactating rats (4 male and 4 female litters) were divided into 2 groups: control--received control liquid diet, and ethanol--received liquid diet containing 4% of ethanol. On postnatal day 24, the pups were killed by decapitation. Liver and brain were utilized for measuring Adenosine Tri-phosphate-citrate lyase and malic enzymes activities. Brain slices were incubated in medium containing glucose to determine glucose consumption and oxidation, and lipid synthesis. The ethanol intake decreased male and female pups' body, brain and liver weight. Liver Adenosine Tri-phosphate-citrate lyase activity was decreased only in male pups of the ethanol group. The intake of ethanol solution by the dams increased glucose consumption and oxidation by the incubated female pups' brain slices and decreased glucose oxidation by the male pups' brain slices. It can be concluded that the effects of maternal ethanol intake on pups' development and metabolism are gender-related.