Alcohol-metabolizing enzymes in placenta and fetal liver: effect of chronic ethanol intake

Epigallocatechin Gallate Ameliorates the Effects of Prenatal Alcohol Exposure in a Fetal Alcohol Spectrum Disorder-Like Mouse Model

Fetal alcohol spectrum disorder is the main preventable cause of intellectual disability in the Western world. Although binge drinking is the most studied prenatal alcohol exposure pattern, other types of exposure, such as the Mediterranean, are common in specific geographic areas. In this study, we analyze the effects of prenatal alcohol exposure in binge and Mediterranean human drinking patterns on placenta and brain development in C57BL/6J mice. We also assess the impact of prenatal treatment with the epigallocatechin-3-gallate antioxidant in both groups. Study experimental groups for Mediterranean or binge patterns: (1) control; (2) ethanol; (3) ethanol + epigallocatechin-3-gallate. Brain and placental tissue were collected on gestational Day 19. The molecular pathways studied were fetal and placental growth, placental angiogenesis (VEGF-A, PLGF, VEGF-R), oxidative stress (Nrf2), and neurodevelopmental processes including maturation (NeuN, DCX), differentiation (GFAP) and neural plasticity (BDNF). Prenatal alcohol exposure resulted in fetal growth restriction and produced imbalances of placental angiogenic factors. Moreover, prenatal alcohol exposure increased oxidative stress and caused significant alterations in neuronal maturation and astrocyte differentiation. Epigallocatechin-3-gallate therapy ameliorated fetal growth restriction, attenuated alcohol-induced changes in placental angiogenic factors, and partially rescued neuronal nuclear antigen (NeuN), (doublecortin) DCX, and (glial fibrillary acidic protein) GFAP levels. Any alcohol consumption (Mediterranean or binge) during pregnancy may generate a fetal alcohol spectrum disorder phenotype and the consequences may be partially attenuated by a prenatal treatment with epigallocatechin-3-gallate.

Placenta as a target of trichloroethylene toxicity

Trichloroethylene (TCE) is an industrial solvent and a common environmental contaminant detected in thousands of hazardous waste sites. Risk of exposure is a concern for workers in occupations that use TCE as well as for residents who live near industries that use TCE or who live near TCE-contaminated sites. Although renal, hepatic and carcinogenic effects of TCE have been documented, less is known about TCE impacts on reproductive functions despite epidemiology reports associating maternal TCE exposure with adverse pregnancy outcomes. Toxicological evidence suggests that the placenta mediates at least some of the adverse pregnancy outcomes associated with TCE exposure. Toxicology studies show that the TCE metabolite, S-(1,2-dichlorovinyl)-l-cysteine (DCVC) generates toxic effects such as mitochondrial dysfunction, apoptosis, oxidative stress, and release of prostaglandins and pro-inflammatory cytokines in placental cell lines. Each of these mechanisms of toxicity have significant implications for placental functions and, thus, ultimately the health of mother and developing child. Despite these findings there remain significant gaps in our knowledge about effects of TCE on the placenta, including effects on specific placental cell types and functions as well as sex differences in response to TCE exposure. Due to the critical role that the placenta plays in pregnancy, future research addressing some of these knowledge gaps could lead to significant gains in public health.

Fetal Cerebral Artery Mitochondrion as Target of Prenatal Alcohol Exposure

Prenatal alcohol exposure results in an array of developmental abnormalities known as fetal alcohol spectrum disorders (FASDs). Despite the high prevalence of FASDs, therapeutic interventions against accidental or intended exposure of developing fetuses to alcohol are limited. This review outlines current knowledge about mitochondria in cerebral blood vessels as a potential target for anti-FASDs intervention. First, it describes the multifaceted role of mitochondria in maintaining the cerebral artery diameter as shown in adult tissue. Second, current literature on alcohol-driven damage of mitochondrial morphology and function in several fetal tissues, including liver, heart, and brain is summarized. The functional consequences of alcohol exposure in these organs include morphological enlargement of mitochondria, increased oxidative stress, and alteration of cellular respiration. These studies point to a tissue-specific effect of alcohol on mitochondrial function and a particular vulnerability of fetal mitochondria to alcohol exposure when compared to adult counterparts. Third, recent work from our group describing persistent changes in fetal baboon cerebral artery proteome following three episodes of prenatal alcohol exposure is reviewed. In conclusion, the consequences of prenatal alcohol exposure on cerebral artery mitochondria constitute an open field of investigation and, eventually, a point of therapeutic intervention against FASDs.

Placental Proteomics Reveal Insights into Fetal Alcohol Spectrum Disorders

BACKGROUND

Fetal alcohol spectrum disorders (FASD) describe many of the well-known neurodevelopmental deficits afflicting children exposed to alcohol in utero. The effects of alcohol on the maternal-fetal interface, especially the placenta, have been less explored. We herein hypothesized that chronic binge alcohol exposure during pregnancy significantly alters the placental protein profile in a rat FASD model.

METHODS

Pregnant rats were orogastrically treated daily with alcohol (4.5 g/kg, gestational day [GD] 5 to 10; 6.0 g/kg, GD 11 to 19) or 50% maltose dextrin (isocalorically matched pair-fed controls). On GD 20, placentae were collected, flash-frozen, and stored until tissues were homogenized. Protein lysates were denatured, reduced, captured on a 10-kDa spin filter, and digested. Peptides were eluted, reconstituted, and analyzed by a Q Exactive™ Hybrid Quadrupole-Orbitrap™ mass spectrometer.

RESULTS

Mass spectrometry (MS) analysis identified 2,285 placental proteins based on normalized spectral counts and 2,000 proteins by intensity-based absolute quantification. Forty-five placental proteins were significantly (p < 0.05) altered by gestational alcohol exposure by both quantification approaches. These included proteins directly related to alcohol metabolism; specific isoforms of alcohol dehydrogenase and aldehyde dehydrogenase were up-regulated in the alcohol group. Ingenuity analysis identified ethanol degradation as the most significantly altered canonical pathway in placenta, and fetal/organ development as most altered function, with increased risk for metabolic, neurological, and cardiovascular diseases. Physiological roles of the significantly altered proteins were related to early pregnancy adaptations, implantation, gestational diseases, fetal organ development, neurodevelopment, and immune functions.

CONCLUSIONS

We conclude that the placenta is a valuable organ not only to understand FASD etiology but it may also serve as a diagnostic tool to identify novel biomarkers for detecting the outcome of fetal alcohol exposure. Placental MS analysis can offer sophisticated insights into identifying alcohol metabolism-related enzymes and regulators of fetal development.

Detrimental effects of ethanol and its metabolite acetaldehyde, on first trimester human placental cell turnover and function

Fetal alcohol spectrum disorder (FASD) describes developmental issues from high maternal alcohol intake, which commonly results in fetal growth restriction and long term morbidity. We aimed to investigate the effect of alcohol and acetaldehyde, on the first trimester placenta, the period essential for normal fetal organogenesis. Normal invasion and establishment of the placenta during this time are essential for sustaining fetal viability to term. We hypothesise that alcohol (ethanol) and acetaldehyde have detrimental effects on cytotrophoblast invasion, turnover and placental function. Taurine is an important amino acid for neuronal and physiological development, and so, its uptake was assayed in cells and placental explants exposed to alcohol or acetaldehyde. First trimester villous explants and BeWo cells were treated with 0, 10, 20, 40 mM ethanol or 0, 10, 20, 40 µM acetaldehyde. The invasive capacity of SGHPL4, a first trimester extravillous cytotrophoblast cell line, was unaffected by ethanol or acetaldehyde (p>0.05; N = 6). The cells in-cycle were estimated using immunostaining for Ki67. Proliferating trophoblast cells treated with ethanol were decreased in both experiments (explants: 40% at 20 mM and 40 mM, p<0.05, N = 8–9) (cell line: 5% at 20 mM and 40 mM, p<0.05, N = 6). Acetaldehyde also reduced Ki67-positive cells in both experiments (explants at 40 µM p<0.05; N = 6) (cell line at 10 µM and 40 µM; p<0.05; N = 7). Only in the cell line at 20 µM acetaldehyde demonstrated increased apoptosis (p<0.05; N = 6). Alcohol inhibited taurine transport in BeWo cells at 10 mM and 40 mM (p<0.05; N = 6), and in placenta at 40 mM (p<0.05; N = 7). Acetaldehyde did not affect taurine transport in either model (P<0.05; N = 6). Interestingly, system A amino acid transport in placental explants was increased at 10 µM and 40 µM acetaldehyde exposure (p<0.05; N = 6). Our results demonstrate that exposure to both genotoxins may contribute to the pathogenesis of FASD by reducing placental growth. Alcohol also reduces the transport of taurine, which is vital for developmental neurogenesis.

A rodent model of low- to moderate-dose ethanol consumption during pregnancy: patterns of ethanol consumption and effects on fetal and offspring growth

It is unknown whether low to moderate maternal alcohol consumption adversely affects postnatal health. The aim of the present study was to develop a rodent model of low-moderate-dose prenatal ethanol (EtOH) exposure. Sprague-Dawley rats were fed a liquid diet with or without 6% v/v EtOH throughout gestation and the pattern of dietary consumption determined. Fetal bodyweights and hepatic alcohol-metabolising gene expression were measured on embryonic Day (E) 20 and offspring growth studied until 1 year. At E8 the plasma EtOH concentration was 0.03%. There was little difference in dietary consumption between the two treatment groups. At E20, EtOH-exposed fetuses were significantly lighter than controls and had significantly decreased ADH4 and increased CYP2E1 gene expression. Offspring killed on postnatal Day (PN) 30 did not exhibit any growth deficits. Longitudinal repeated measures of offspring growth demonstrated slower growth in males from EtOH-fed dams between 7 and 12 months of age; a cohort of male pups killed at 8 months of age had a reduced crown-rump length and kidney weight. In conclusion, a liquid diet of 6% v/v EtOH fed to pregnant dams throughout gestation caused a 3-8% reduction in fetal growth and brain sparing, with growth differences observed in male offspring later in life. This model will be useful for future studies on the effects of low-moderate EtOH on the developmental origins of health and disease.

Cellular and mitochondrial effects of alcohol consumption

Alcohol dependence is correlated with a wide spectrum of medical, psychological, behavioral, and social problems. Acute alcohol abuse causes damage to and functional impairment of several organs affecting protein, carbohydrate, and fat metabolism. Mitochondria participate with the conversion of acetaldehyde into acetate and the generation of increased amounts of NADH. Prenatal exposure to ethanol during fetal development induces a wide spectrum of adverse effects in offspring, such as neurologic abnormalities and pre- and post-natal growth retardation. Antioxidant effects have been described due to that alcoholic beverages contain different compounds, such as polyphenols as well as resveratrol. This review analyzes diverse topics on the alcohol consumption effects in several human organs and demonstrates the direct participation of mitochondria as potential target of compounds that can be used to prevent therapies for alcohol abusers.

Liquid-diet with alcohol alters maternal, fetal and placental weights and the expression of molecules involved in integrin signaling in the fetal cerebral cortex

Maternal alcohol consumption during pregnancy causes wide range of behavioral and structural deficits in children, commonly known as Fetal Alcohol Syndrome (FAS). Children with FAS may suffer behavioral deficits in the absence of obvious malformations. In rodents, the exposure to alcohol during gestation changes brain structures and weights of offspring. The mechanism of FAS is not completely understood. In the present study, an established rat (Long-Evans) model of FAS was used. The litter size and the weights of mothers, fetuses and placentas were examined on gestation days 18 or 20. On gestation day 18, the effects of chronic alcohol on the expression levels of integrin receptor subunits, phospholipase-Cγ and N-cadherin were examined in the fetal cerebral cortices. Presence of alcohol in the liquid-diet reduced the consumption and decreased weights of mothers and fetuses but increased the placental weights. Expression levels of β₁ and α₃ integrin subunits and phospholipase-Cγ₂ were significantly altered in the fetal cerebral cortices of mothers on alcohol containing diet. Results show that alcohol consumption during pregnancy even with protein, mineral and vitamin enriched diet may affect maternal and fetal health, and alter integrin receptor signaling pathways in the fetal cerebral cortex disturbing the development of fetal brains.

Increased ethanol intake after prenatal ethanol exposure: studies with animals

This review analyses the most relevant studies in which ethanol intake was measured after prenatal exposure to the drug. Despite the variety in methodology, in most such studies this prenatal experience induced a higher consumption of ethanol. Several variables that may affect the expression of this phenomenon are discussed, such as gender, age at testing, period of ethanol exposure, ethanol dose and conditions during the test. The mechanisms proposed in all these studies to explain the increased ethanol intake effect are also discussed. Some of these mechanisms are related to the teratological effects of the drug on the neurochemical systems involved in the reinforcing effects of abuse drugs, as well as on the regulatory systems of stress response. Another explanation of this phenomenon is also proposed in terms of associative learning. Specifically, the increased ethanol intake effect may be the result of a conditioned preference for ethanol acquired by the fetus when exposed to the drug during the last days of gestation.

The importance of alcohol misuse, malnutrition and genetic susceptibility on brain growth and plasticity

The "dyad: alcoholic mother and foetus" is a very complex entity in which several elements such as genes, metabolism, diet, drugs and social habits play a role at different stages in the development of the fetal brain damage. The literature on the effects of alcohol consumption on the developing brain is extensive but very few evidences have been reported regarding the combined neurotoxic effects of poor nutrition and alcohol consumption. The consequences of ethanol intake alone or combined with poor maternal nutrition appear to be severe and life-long. Alcohol exerts its neurotoxic effects on the developing brain directly by acting on fetal brain tissues, and indirectly either by interfering with placental physiology or by impairing the mother's physiology. Alcohol misuse in pregnancy is also frequently associated with other conditions that can potentially increase the brain damage such as poor nutrition and smoking. This article reviews the effects of poor nutrition and alcohol misuse during pregnancy on the development of the fetal brain and discusses the cumulative effects of these two environmental factors and their interaction with maternal and fetal genetic make-ups.

Prenatal ethanol exposure has differential effects on fetal growth and skeletal ossification

There is increasing evidence suggesting that the intrauterine environment may influence long-term bone health and the risk of developing osteoporosis in later life. Alcohol (ethanol) is one factor whose presence in the prenatal environment has long-term consequences for the offspring, including permanent growth retardation. Moreover, prenatal ethanol exposure retards both fetal and postnatal bone development. It is unknown if ethanol's effects on skeletal development result from generalized growth retardation or effects specific to skeletal development. Furthermore, the level of ethanol exposure required to produce skeletal effects is unknown. The objectives of this study were to determine (1) if ethanol exerts specific effects on fetal skeletal development that are independent from its effects on general growth, and (2) the level of prenatal ethanol exposure required to affect fetal growth and skeletal ossification. Rats were fed isocaloric diets with ethanol (15%, 25%, or 36% ethanol-derived calories (EDC), approximating low, moderate, and high exposure levels), or without ethanol (pair-fed, PF, or control, C groups), prior to and throughout 21 days of gestation. The degree of E-induced delay in development was determined by comparison of E fetuses on d21 gestation to C fetuses on d17-d21 gestation. Prenatal ethanol exposure at 36% EDC decreased fetal body weight, length, and skeletal ossification compared with PF and C fetuses on d21 gestation. Importantly, effects on ossification, but not body weight or length, were also seen at the more moderate dose of 25% EDC, and the number of bones affected and the severity of effects on ossification tended to increase with dose of ethanol. Comparison of E fetuses on d21 gestation with C fetuses from d17 to 21 gestation indicated that the ethanol-induced delay in development differed for weight and skeletal ossification, and was not uniform among skeletal sites. Taken together, these data suggest that prenatal ethanol exposure has effects on fetal skeletal development that are independent of those on overall fetal growth, and that these effects occur even at moderate levels of maternal drinking. Effects of prenatal ethanol exposure on fetal skeletal development could potentially increase the offspring's risk of osteoporosis later in life.

Ethanol in utero induces epithelial cell damage and altered kinetics in the developing rat intestine

The effect of prenatal ethanol exposure on the intestinal maturation of rat fetuses was investigated to understand the nutritional alterations found in the offspring of alcoholic mothers. Female Wistar rats were maintained on solid diet and 25% ethanol solution as drinking fluid during pregnancy, and non-alcoholic isocaloric pregnant mothers were used as controls. At birth, intestines from unsuckled pups were removed for study. The weight and length of the intestine decreased significantly when ethanol was present in utero. Ultrastructural evaluation of the epithelium revealed loss of contact between neighboring enterocytes and abnormal dilation of the cisternae of the Golgi apparatus in ethanol-exposed pups. Further, increased lysosome-like vesiculation and enhanced lysosomal beta-galactosidase activity was observed in these neonates. The total number of absorptive enterocytes in the epithelium was reduced by 30% in ethanol-exposed neonates as compared to controls, due to altered cell growth and death during fetal life. Ethanol in utero stimulated epithelial cell migration which compensated cell loss, as demonstrated by 5'-Bromodeoxyuridine labeling. These findings could have important implications for the assimilation of nutrients and failure to thrive in infants with fetal alcohol syndrome.

Changes in the enterocyte cytoskeleton in newborn rats exposed to ethanol in utero

BACKGROUND

Cytoskeletal changes after longterm exposure to ethanol have been described in a number of cell types in adult rat and humans. These changes can play a key part in the impairment of nutrient assimilation and postnatal growth retardation after prenatal damage of the intestinal epithelium produced by ethanol intake.

AIMS

To determine, in the newborn rat, which cytoskeletal proteins are affected by longterm ethanol exposure in utero and to what extent.

ANIMALS

The offspring of two experimental groups of female Wistar rats: ethanol treated group receiving up to 25% (w/v) of ethanol in the drinking fluid and control group receiving water as drinking fluid.

METHODS

Single and double electron microscopy immunolocalisation and label density estimation of cytoskeletal proteins on sections of proximal small intestine incubated with monoclonal antibodies against actin, alpha-tubulin, cytokeratin (polypeptides 1, 5, 6, 7, 8, 10, 11, and 18), and with a polyclonal antibody anti-beta 1,4-galactosyl transferase as trans golgi (TG) or trans golgi network (TGN) marker, or both. SDS-PAGE technique was also performed on cytoskeletal enriched fractions from small intestine. Western blotting analysis was carried out by incubation with the same antibodies used for immunolocalisation.

RESULTS

Intestinal epithelium of newborn rats from the ethanol treated group showed an overexpression of cytoskeletal polypeptides ranging from 39 to 54 kDa, affecting actin and some cytokeratins, but not tubulin. Furthermore, a cytokeratin related polypeptide of 28-29 kDa was identified together with an increase in free ubiquitin in the same group. It was noteworthy that actin and cytokeratin were abnormally located in the TG or the TGN, or both.

CONCLUSIONS

Longterm exposure to ethanol in utero causes severe dysfunction in the cytoskeleton of the developing intestinal epithelium. Actin and cytokeratins, which are involved in cytoskeleton anchoring to plasma membrane and cell adhesion, are particularly affected, showing overexpression, impaired proteolysis, and mislocalisation.

Placental transfer of selected substances of abuse

The placenta was classically considered a barrier, but in 1957 this notion was shattered. This organ is only a selective filter and metabolic site. In this review, the placental transfer of the top 17 substances of abuse are analyzed. In the National Library of Medicine only 41 papers that documented placental transfer of the major substances of abuse could be located, and these data excluded approximately one-sixth of the most commonly abused substances. Nonetheless, it was possible to evaluate placental transfer of all substances of abuse based on their physical chemical properties. It is with despair that it must be reported that virtually all substances of abuse freely cross the placenta, exposing the embryo/fetus to whatever substances the mother may be using.

Liver alcohol dehydrogenase activity and ethanol levels during chronic ethanol intake in pregnant rats and their offspring

The effects of chronic alcohol intake on the ethanol levels in body fluids (blood, amniotic fluid, and fetal intragastric content), hepatic alcohol dehydrogenase (ADH) activity, isoenzyme distribution, and hepatic zinc levels were studied in pregnant rats at term (19 and 21 days), in their offspring at fetal, perinatal, and weaned stages, and in adult virgin rats. Three experimental groups were studied: 1) the alcohol group received ethanol in drinking water (from 10% to 25% over 2 months), 2) the fibre diet group was undernourished on a hypocaloric diet, to assess the effects of malnutrition associated with chronic alcohol intake, and 3) the control group received no alcohol and normal diet. A gradient of increasing ethanol concentrations was found in fetal blood, amniotic fluid, and fetal intragastric contents with respect to maternal blood. A decrease in ADH activity was found in alcohol-consuming pregnant rats compared to controls. This was related neither to liver ADH isoenzyme distribution nor to changes in hepatic zinc levels. Chronic alcohol consumption in pregnant rats produced high ethanol accumulation in fetal fluids and changes in the liver ADH activity depending on the physiological situation (pregnancy, development, virgin state).

A surprising effect of paternal alcohol treatment on rat fetuses

Male rats were intubated with either 5, 2.5, or 0 g/kg alcohol. Animals in the latter two groups were pairfed to those in the 5 g/kg group. A fourth group of males was not treated and was fed ad lib. Males were bred once after 3 weeks of intubation and twice after 9 weeks of intubation. Females in the first two breedings were sacrificed prior to delivery, whereas females in the last breeding were allowed to deliver their litters. There were no significant decreases in male fertility or litter size, but fecundity was reduced in females bred to alcohol-treated males when all breedings were pooled. Newborn weights (third breeding) were not significantly affected by paternal alcohol treatment, but fetal weights in the first two breedings were significantly increased in association with paternal alcohol treatment. There was also an alcohol-related increase in the number of male fetuses in breeding one, and an increase in placental weights in breeding two; the placental index (placental weight/fetal weight) was also decreased by paternal alcohol treatment for fetuses in the second breeding. These results suggest paternal alcohol treatment can have effects on offspring body weights, which are not observable once females have given birth.

Effect of postnatal ethanol exposure on expression of differentiation antigens of murine splenic lymphocytes

Ethanol is a recognized immunosuppressive agent in the chronic alcoholic. However, the effects of ethanol exposure on the developing immune system have not been extensively investigated. This study evaluated the effects of early postnatal ethanol exposure, via breast milk, on splenic lymphocyte differentiation antigen expression in offspring reared by ethanol-fed mice. Maternal mice were fed a liquid diet containing 20% ethanol-derived calories during pregnancy (E-P), pregnancy and lactation (E-PL), or lactation (E-L). Ad libitum-fed (C) and pair-fed (PF) control groups, fed a control liquid diet, were included. Expression of differentiation antigens on splenic lymphocytes from 21-day-old offspring reared by females in 1 of the 3 ethanol exposure conditions was evaluated by flow cytometry. Offspring reared by E-P females had similar numbers of splenic lymphocytes as offspring reared by C and pair-fed during pregnancy (PF-P) females. In contrast, offspring reared by E-PL and E-L females had fewer splenic lymphocytes than both PF-PL and PF-L (respectively), and C offspring. The number of Thy 1.2+, CD4+, CD8+, and IgG+ (B-cell) splenic lymphocytes was reduced in E-PL and E-L offspring compared with PF and C offspring. E-P offspring had fewer CD4+ and IgG+ splenic lymphocytes than C, but not PF-P, offspring. The percentage of Thy 1.2+ splenic lymphocytes was significantly reduced among E-PL and E-L offspring compared with PF-PL and PF-L (respectively), and C offspring.(ABSTRACT TRUNCATED AT 250 WORDS)

Alterations in brain polyribosomal RNA translation and lymphocyte proliferation in prenatal ethanol-exposed rats

The long-term effects of prenatal ethanol exposure on the properties of brain polysomes and the proliferative responses of lymphocytes to mitogenic stimulation in adult offspring were assessed. Female Sprague-Dawley rats either ingested the control or 6.6% ethanol-containing Lieber-DeCarli liquid diet during the 3rd trimester of pregnancy. Controls were age-matched and pair-fed. At 42 to 72 days of age, ethanol effects were evaluated on the (1) polysomal properties in the cerebral hemispheres, cerebellum, and hippocampal regions of the brain after translation in a messenger RNA (mRNA)-dependent rabbit reticulocyte lysate system and (2) immunologic functions of lymphocytes cultured from spleen cells by measuring their responses to mitogenic stimulation. Results showed long-term adverse effects of in utero ethanol exposure on the polysomal RNA translation in each of the three brain regions tested with free polysomal mRNAs affected more than the bound polysomal mRNAs. Of these, the hippocampal region appeared to sustain the most injurious effects. In addition, a suppression of the mitogen-induced lymphocyte proliferative responses were present under these conditions. The degree of suppression varied with the specific mitogen used. Data suggest that the ethanol effects on the CNS and lymphocyte proliferation are most possibly irreversible, and in the case of the CNS, a post-translational modification by ethanol is indicated. The reduced lymphocyte responses are suggestive of a possible interference by ethanol of the synthesis of interleukin-2 (IL-2) and/or a reduced binding of IL-2 with its receptor (IL-2 receptors).

Alcohol exposure before pregnancy: biochemical and behavioral effects on the offspring of rats

The effect of maternal alcohol exposure before mating was investigated in the offspring over a period of 6 months concerning some specific aspects of energy metabolism in the brain and the liver. The following biochemical parameters were analyzed: superoxide dismutase (involved in elimination of free radicals produced during ethanol oxidation), enolase isoenzymes (markers of nerve cell maturation), and alcohol and aldehyde dehydrogenase (the main alcohol degradating enzymes). These enzymatic activities were measured at their subcellular level. In these animals never directly exposed to alcohol, superoxide dismutase activity was decreased mainly in the liver cytosol. Only the nonneuronal form of enolase activity was modified. Alcohol dehydrogenase was decreased in the liver as well as in the brain. Aldehyde dehydrogenase was also decreased in the liver and in the brain, mainly in the mitochondria. Behavioral observations showed decreased emotional reactivity as well as an increase in locomotor activity. Our results suggest that long-lasting biochemical and behavioral effects of alcohol may occur in the offspring starting at the earliest stage of development.

Prenatal exposure to ethanol alters the synthesis and glycosylation of proteins in fetal hepatocytes

In the present work we have studied the effect of prenatal exposure to alcohol on the synthesis, glycosylation, and transport of proteins in fetal hepatocytes isolated from 21-day-old fetuses derived from control and chronic alcoholic rats. Protein synthesis was evaluated both in a cell-free system and in hepatocytes after (35S)methionine and (3H)leucine incorporation, respectively. Glycosylation was assessed using (3H)mannose and (3H)galactose as precursors. Protein synthesis was significantly decreased in treated hepatocytes. In control hepatocytes, quantitative electron microscope autoradiography showed that both (3H)leucine and (3H)mannose incorporation occur first in the rough endoplasmic reticulum (rER). Later the silver grains appeared over the Golgi apparatus, and, finally there was a transport towards the cell periphery. After pulse, silver grains corresponding to (3H)galactose incorporation appeared over the Golgi apparatus. The label then moved to the hepatocyte periphery. Alcohol treated hepatocytes showed a retention of grains over the Golgi apparatus with a diminution in the label at the cell periphery. These results indicate that prenatal exposure to alcohol induces a decrease in the synthesis of proteins in the hepatocyte as well as an alteration in the process of glycosylation and/or transport of secretory proteins.

Presence of cytosolic aldehyde dehydrogenase isozymes in adult and fetal rat liver

A colony of Wistar-strain rats bred at Purdue University was composed of animals with two different isozyme patterns of liver cytosolic aldehyde dehydrogenase (EC 1.2.1.3, ALDH) as determined by isoelectric focusing. One cytosolic isozyme pattern had a major activity band with a pI = 5.8 and a minor activity band at pI = 6.2. The other pattern contained three major isozymes with pI values of 5.3, 5.4 and 5.6 along with the pI 6.2 isozyme and a trace of the 5.8 one. The 5.8 and 6.2 isozymes were recognized by antibodies produced against horse and beef liver cytosolic ALDH, whereas the set of three (5.3-5.6) were not. The cytosolic isozymes were inhibited by low levels of disulfiram and had Km values for acetaldehyde in the 100 microM range, properties typical for cytosolic ALDHs. All animals contained the same isozymes of liver mitochondrial ALDH. These were a major activity with a pI = 5.2 and minor activities associated with isozymes of pI = 6.4 and 6.6. These isozymes were recognized by antibodies produced against pure horse and beef liver mitochondrial ALDHs. Both cytosolic and mitochondrial ALDHs were found in fetal liver as early as day 15 of gestation. The total activity for mitochondrial ALDH increased between day 15 and day 21 whereas that for cytosolic ALDHs remained relatively constant during development. It appeared that both cytosolic and mitochondrial ALDH were present by at least the third trimester and could afford the fetus some protection against the toxic action of endogenous or exogenous aldehydes.

Prenatal brain malformations following acute ethanol exposure in the rat

Morphology of the cerebral cortex was studied in fetuses on gestational Day 21 following oral administration of several doses of ethanol (for total doses of 10, 15, or 18 g/kg) to pregnant rats on gestational Days 14 and 15, a critical period for the development of the cerebral cortex. All doses of ethanol were associated with a reduction in maternal weight gain, fetal body weight, and placental weight. Only the high dose of ethanol (total dose 18 g/kg) caused significant fetal cortical thinning. Acute exposure of pregnant rats to ethanol produced dose-dependent malformations of the cerebral cortex and hippocampus in fetuses. On gestational Day 21, the 18 g/kg group contained fetuses with severely disorganized cortical architecture, heterotopias of the cerebral cortex, pia and choroid plexus, and status verrucosus deformis. Fetuses from the 10 g/kg group had less severe malformations, such as disorganization of layers of cortical neurons and dentate granule cells while fetuses from the 15 g/kg group had a mixture of severe and minor malformations. This study demonstrates that acute ethanol exposure during a critical period of development in rats can result in brain malformations similar to those reported in human fetuses and neonates from alcoholic mothers.

Comparative metabolic effects of chronic ethanol intake and undernutrition in pregnant rats and their fetuses

Female rats receiving ethanol in the drinking water before and during gestation (ET) were compared to pair-fed animals (PF) and normal controls (C) fed ad libitum. On the 21st day of gestation the maternal body and liver weight, blood glucose, and plasma protein concentrations were lower in ET and PF animals as compared to C. In contrast to C or PF mothers, ET-fed mothers had higher circulating beta-hydroxybutyrate and triacyglyceride levels and beta-hydroxy-butyrate/acetoacetate ratio. Liver triacylglycerides were increased whereas liver glycogen concentration was reduced in ET-fed animals. Only fetal body and liver weights and blood glucose were lower in both ET and PF than in C. Blood beta-hydroxybutyrate was increased and liver glycogen was decreased only in ET fetuses. There were no differences among the groups in fetal circulating beta-hydroxy-butyrate/acetoacetate ratio, plasma proteins, and triacylglycerides or liver triacyglyceride content. Results indicate that certain changes in ET mothers are specifically produced by the ethanol intake rather than undernutrition. Further, metabolic changes occurring in the fetus are influenced by the ethanol effects in the mother and these actions may be added to those directly produced by the ethanol crossing the placenta. However, the collaterals were three times more likely to report more drinking days than the patients; 40.4% (86/213) of the cohabiting contacts reported more drinking days compared to 12.7% (27/213) of the patients reporting more drinking days (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

The role of maternal alcohol damage on ethanol teratogenicity in the rat

To study the severity and degree of in utero alcohol effects in relation to the rate of maternal alcohol damage, multiparous 1-year alcohol-fed rats were used, with an appropriate pair-fed control group. During pregnancy, alcoholic dams showed relatively high acetaldehyde levels (41 +/- 19 mumol/l) and blood alcohol levels of 22.8 +/- 14 mmol/l. They also showed marked histological alterations in liver as well as high serum aspartate-aminotransferase, alanine-aminotransferase, alkaline phosphatase, glutamate dehydrogenase, and gamma-glutamyltransferase activities. The increase in serum enzyme levels did not correlate with an increase in hepatic enzyme levels since only glutamate dehydrogenase was enhanced in liver after 1 year of alcohol intake. In addition, except for an increase in low Km aldehyde dehydrogenase activity, there were no changes in liver alcohol metabolizing enzymes in chronic alcohol vs. pair-fed females. Alcoholic rats showed a high incidence of damage in their progeny (resorptions, immature fetuses, decrease in fetal weight, etc.), and rats with the highest serum levels of the above enzymes (especially glutamate dehydrogenase and gamma-glutamyl transferase) had severely affected progeny. Rats with minimal histological liver damage, in contrast, did not show resorptions. Thus, the results presented suggest that the stage of maternal alcohol illness, as indicated mainly by the extent of liver damage, plays an important role in the frequency and severity of in utero alcohol effects in the rat.

Polyamines and diamine oxidase activity in maternal, embryonal, and fetal tissues of rat after chronic ethanol consumption

The effects of maternal ethanol consumption for 4 weeks before and throughout gestation on polyamine content and diamine oxidase activity of maternal, embryonal and fetal tissues are reported. At the 12th day of pregnancy, a decrease of putrescine in the liver of the mother and marked increases in putrescine, cadaverine and spermidine in embryos were observed. At day 18, putrescine and cadaverine diminished in maternal liver and placenta, and no changes in amine content in fetal liver and brain were found. At day 12, diamine oxidase activity increased in maternal liver and placenta, whereas it greatly diminished in embryos. At day 18, enzyme activity decreased in maternal liver, placenta, fetal liver and brain. These results indicate that chronic ethanol ingestion induces alterations in polyamine concentrations and metabolism in growing and developing tissues during pregnancy that might contribute to the adverse effect of ethanol on conceptual development.