Effect of Duration of Maternal Alcohol Consumption on Calcium Metabolism and Bone in the Fetal Rat

Sexually dimorphic effects of prenatal alcohol exposure on the murine skeleton

BACKGROUND

Prenatal alcohol exposure (PAE) can result in lifelong disabilities known as foetal alcohol spectrum disorder (FASD) and is associated with childhood growth deficiencies and increased bone fracture risk. However, the effects of PAE on the adult skeleton remain unclear and any potential sexual dimorphism is undetermined. Therefore, we utilised a murine model to examine sex differences with PAE on in vitro bone formation, and in the juvenile and adult skeleton.

METHODS

Pregnant C57BL/6J female mice received 5% ethanol in their drinking water during gestation. Primary calvarial osteoblasts were isolated from neonatal offspring and mineralised bone nodule formation and gene expression assessed. Skeletal phenotyping of 4- and 12-week-old male and female offspring was conducted by micro-computed tomography (µCT), 3-point bending, growth plate analyses, and histology.

RESULTS

Osteoblasts from male and female PAE mice displayed reduced bone formation, compared to control (≤ 30%). Vegfa, Vegfb, Bmp6, Tgfbr1, Flt1 and Ahsg were downregulated in PAE male osteoblasts only, whilst Ahsg was upregulated in PAE females. In 12-week-old mice, µCT analysis revealed a sex and exposure interaction across several trabecular bone parameters. PAE was detrimental to the trabecular compartment in male mice compared to control, yet PAE females were unaffected. Both male and female mice had significant reductions in cortical parameters with PAE. Whilst male mice were negatively affected along the tibial length, females were only distally affected. Posterior cortical porosity was increased in PAE females only. Mechanical testing revealed PAE males had significantly reduced bone stiffness compared to controls; maximum load and yield were reduced in both sexes. PAE had no effect on total body weight or tibial bone length in either sex. However, total growth plate width in male PAE mice compared to control was reduced, whilst female PAE mice were unaffected. 4-week-old mice did not display the altered skeletal phenotype with PAE observed in 12-week-old animals.

CONCLUSIONS

Evidence herein suggests, for the first time, that PAE exerts divergent sex effects on the skeleton, possibly influenced by underlying sex-specific transcriptional mechanisms of osteoblasts. Establishing these sex differences will support future policies and clinical management of FASD.

Altered bone and body composition in children and adolescents with confirmed prenatal alcohol exposure

Prenatal alcohol exposure can contribute to long term adverse health outcomes. Development of the skeletal system begins at the early embryonic stage and continues into early adulthood but the effect of prenatal alcohol exposure on skeletal growth is relatively unexplored in a clinical population. Here, we performed dual X-ray absorptiometry to examine bone, fat, and muscle accrual in children and adolescents diagnosed with, or at risk of, fetal alcohol spectrum disorders (FASDs). Children (aged 4-9 years) with FASD or at risk of FASD (n = 10) had similar growth to age matched controls (n = 27). By adolescence (aged ≥10 years), those with FASDs (n = 13) were shorter and had lower areal bone mineral density and lean tissue mass than typically developing peers (n = 29). Overall, adolescents diagnosed with FASDs had greater odds of impairments to bone and body composition. These findings highlight the importance of early FASD diagnosis and appropriate post-diagnostic medical follow-up to enable timely, effective interventions to optimize bone and body composition during paediatric growth.

Abnormal growth and morphogenesis of placenta at term is linked to adverse fetal development after perigestational alcohol consumption up to early gestation in mouse

BACKGROUND

Gestation alcohol consumption produces fetal growth restriction and malformations by affecting the embryo-fetal development. Recently a relationship between abnormal placentation and fetal malformation and intrauterine growth retardation has been suggested. However, the effects of perigestational alcohol ingestion up to early pregnancy on the placenta at term and its association with fetal abnormalities are little known.

METHODS

In female mice, ethanol 10% in water was administered for 15 days previous and up to days 4 (D4), 8 (D8), or 10 (D10) of gestation (TF), and gestation continues without ethanol exposure. Control females (CF) received ethanol-free water. At day 18, feto-placental units and implantation sites were studied.

RESULTS

TF had increased resorptions and only fetuses from D8-TF and D10-TF had significantly increased weights versus CF. D4 and D10-TF-placentas had significantly reduced weights. All TF had increased junctional zone (JZ) and reduced labyrinth (Lab) areas (PAS-histology and morphometry) compared with CF. Fetuses with mainly with craniofacial abnormalities and skeletal defects (Alizarin red staining), significantly increase; while the fetal bone density (alizarin color intensity, ImageJ) was reduced in D4, D8 and D10-TF versus CF. Although all TF-placentas were histo-structural affected, TF-abnormal fetuses had the most severe placental anomalies, with junctional abundant glycogenic cells into the labyrinth, disorganized labyrinthine vascularization with signs of leukocyte infiltrates and feto-maternal blood mix.

CONCLUSIONS

Perigestational alcohol consumption up to early gestation induces at term fetal growth alterations, dysmorphology and defective skeleton, linked to deficient growth and abnormal morphogenesis of placenta, highlighting insight into the prenatal etiology of FASD.

Maternal Vitamin D Status and Gestational Weight Gain as Correlates of Neonatal Bone Mass in Healthy Term Breastfed Young Infants from Montreal, Canada

The implications of maternal gestational weight gain (GWG) and vitamin D status to neonatal bone health are unclear. We tested whether maternal 25-hydroxyvitamin D (25(OH)D) and GWG relate to neonatal bone mineral content (BMC) and bone mineral density (BMD). Healthy term appropriate for gestational age breastfed neonates (n = 142) and their mothers were recruited 24–36 h after delivery and followed at 1.0 ± 0.5 month. At birth, obstetric data were collected and newborn serum 25(OH)D was measured. At 1 month, neonatal whole-body (WB) BMC, WB BMC relative to body weight (WB BMC/kg), lumbar spine BMC and BMD, maternal and neonatal 25(OH)D concentrations, and anthropometry were measured. Infant BMC and BMD between maternal 25(OH)D (<50, ≥50 nmol/L) and GWG (insufficient, adequate, and excessive) categories were compared. Maternal 25(OH)D was not related to infant whole-body BMC, BMC/kg, lumbar spine BMC, and BMD. Infants in the excessive maternal GWG category had greater (p = 0.0003) whole-body BMC and BMC/kg and lumbar spine BMC and BMD than inadequate GWG, and greater (p = 0.0063) whole-body BMC/kg and lumbar spine BMC and BMD than adequate GWG. These results suggest that maternal GWG, but not vitamin D status, modestly relates to bone mass in neonates.

Enamel neonatal line thickness in deciduous teeth of Australian children from known maternal health and pregnancy conditions

BACKGROUND

Physiological disruptions to early human development have implications for health and disease in later life. Limited research has explored how prenatal factors influence dental development in children of mothers with known pregnancy conditions. Enamel in human deciduous teeth begins forming in utero and is highly susceptible to physiological upsets experienced perinatally. The moment of birth itself is marked in deciduous enamel by the Neonatal Line (NNL) as a baby transitions from the uterine to external environment. This study evaluates the effect of maternal health factors that include stress and alcohol consumption on NNL in teeth from Australian children.

STUDY DESIGN AND SUBJECTS

Mothers (n = 53) were interviewed about their health during pregnancy and experience of birth. Sixty-five deciduous teeth (incisors, molars, one canine) from their children were donated for histological examination. Neonatal line thickness was measured from thin sections and evaluated against maternal and neonatal factors using statistical analyses, controlling for tooth type and birth number.

RESULTS AND CONCLUSIONS

The only maternal factor of a statistically significant effect on NNL thickness was alcohol consumption. Children of mothers who drank occasionally during pregnancy had a thicker NNL when compared to children of mothers who abstained. These results suggest that maternal lifestyle factors influence NNL formation possibly due to physiological changes that disrupt calcium homeostasis during enamel deposition. We highlight large intra-specific variation in human NNL expression. The potential of dental sampling in identifying children with prenatal exposure to alcohol is suggested.

Role of TGFβ Signaling in Maternal Ethanol-Induced Fetal Articular Cartilage Dysplasia and Adult Onset of Osteoarthritis in Male Rats

Based on our previous findings that prenatal ethanol exposure in offspring increased susceptibility to adult osteoarthritis, this study aimed to further investigate the direct toxicity of ethanol on fetal articular cartilage development. Rat bone marrow-derived stroma cells were capsulated in alginate beads, incubated in a chondrogenic differentiation medium, and cultured for 4 weeks with ethanol treatment at concentrations of 0, 4, 20, and 100 mM. Pregnant rats were treated with ethanol (4 g/kg/day) from gestational days (GDs) 9 to 20. At GD20 and postnatal weeks 2, 6, and 12, 8 male offspring were sacrificed, and 8 male offspring rats of 8-weeks old in each group were treated with or without intraarticular injection of papain for 4 weeks to verify the susceptibility of adult osteoarthritis. Ethanol treatment resulted in poor differentiation of bone marrow-derived stroma cells to chondrocytes and suppressed the expression of the transforming growth factor-β (TGFβ)-smad2/3-Sox9 signaling pathway. In animal experiments, the shape of articular cartilage in the ethanol treatment group was more disordered than that of the control group, the matrix was not deep, and the cartilage was thin, which showed poor cartilage development. The TGFβ signaling pathway in the ethanol treatment group was persistently low at all time points. After intraarticular injection of papain, histological analyses, and the Mankin score revealed increased cartilage destruction in the ethanol treatment group. Ethanol caused articular cartilage dysplasia that was programmed in adulthood via a low-functional TGFβ signaling pathway, and the tolerance of this articular cartilage to external stimuli was significantly decreased.

Prenatal alcohol exposure reduces mandibular calcium and phosphorus concentrations in newborn rats

Previous studies suggest that prenatal alcohol exposure affects fetal bone development, including bone quality. This study evaluated the chemical composition of mandibles from newborn rats after maternal 20% alcohol consumption before and throughout gestation. Nine rats were initially distributed into three groups: an Alcohol group, Pair-fed group, and Control group. The groups were fed prespecified diets for 8 weeks before and the 3 weeks during pregnancy. At age 5 days, eight newborns from each group were euthanized (total, n = 24). Using energy dispersive spectrometry, we evaluated samples of mandibles from newborns to identify changes in bone mineralization, specifically Ca and P concentrations. Ca and P concentrations were lower in the Alcohol group than in the Control and Pair-fed groups (P = 0.003 and P = 0.001, respectively). In summary, alcohol exposure before and throughout gestation reduces mandibular Ca and P concentrations in newborn rats. (J Oral Sci 58, 439-444, 2016).

Relation of Heavy Alcohol Consumption to QTc Interval Prolongation

Until now, few studies have examined QT intervals in subjects who consume alcohol. We performed this study to evaluate the associations between alcohol consumption and the QTc interval based on a general population. A total of 11,269 adults were examined using a multistage cluster sampling method to select a representative sample of subjects aged ≥35 years. Participants were asked to provide information about their alcohol consumption, and all participants received electrocardiograms and echocardiograms. A prolonged QTc interval was defined according to the national guidelines, which specify thresholds of ≥460 ms in women and ≥450 ms in men. Patients were divided into 3 categories, based on the amount of alcohol they consumed: heavy drinkers (>15 g/day for women and >30 g/day for men), moderate drinkers (≤15 g/day for women and ≤30 g/day for men), and nondrinkers (0 g/day). The results showed that the heavy drinkers had longer QTc intervals than did the nondrinkers. Multivariate logistic regression analyses revealed that men who were heavy drinkers had approximately 1.4-fold higher odds of having a prolonged QTc interval (odds ratio 1.431, 95% confidence interval [CI] 1.033 to 1.982, p = 0.031) than nondrinkers; in women, heavy drinkers had ∼2.3-fold higher odds of having a prolonged QTc interval (odds ratio 2.344, 95% CI 1.202 to 4.571, p = 0.012) than nondrinkers. Neither men nor women who were moderate drinkers exhibited a significant increase in risk for prolonged QTc interval. In conclusion, heavy alcohol consumption was found to be a risk factor for a prolonged QTc interval.

The role of acidemia in maternal binge alcohol-induced alterations in fetal bone functional properties

BACKGROUND

Heavy alcohol consumption during pregnancy negatively impacts the physical growth of the fetus. Although the deleterious effects of alcohol exposure during late gestation on fetal brain development are well documented, little is known about the effect on fetal bone mechanical properties or the underlying mechanisms. The purpose of this study was to investigate the effects of late gestational chronic binge alcohol consumption and alcohol-induced acidemia, a critical regulator of bone health, on functional properties of the fetal skeletal system.

METHODS

Suffolk ewes were mated and received intravenous infusions of saline or alcohol (1.75 g/kg) over 1 hour on 3 consecutive days per week followed by 4 days without treatment beginning on gestational day (GD) 109 and concluding on GD 132 (term = 147 days). The acidemia group was exposed to increased inspired fractional concentrations of CO2 to closely mimic the alcohol-induced decreases in maternal arterial pH seen in the alcohol group.

RESULTS

Fetal femurs and tibias from the alcohol and acidemia groups were ~3 to 7% shorter in length compared with the control groups (p < 0.05). Three-point bending procedure demonstrated that fetal femoral ultimate strength (MPa) for the alcohol group was decreased (p < 0.05) by ~24 and 29%, while the acidemia group exhibited a similar decrease (p < 0.05) of ~32 and 37% compared with the normal control and saline control groups, respectively. Bone extrinsic and intrinsic mechanical properties including maximum breaking force (N) and normalized breaking force (N/kg) of fetal bones from the alcohol and acidemia groups were significantly decreased (p < 0.05) compared with both control groups.

CONCLUSIONS

We conclude that late gestational chronic binge alcohol exposure reduces growth and impairs functional properties of the fetal skeletal system and that the repeated episodes of alcohol-induced maternal acidemia may be at least partially responsible for these effects.

Long-term depression in vivo: effects of sex, stress, diet, and prenatal ethanol exposure

Long-term depression (LTD) of synaptic efficacy has proven a difficult phenomenon to examine in vivo, despite the ease with which it is induced in a variety of in vitro preparations. Prior exposure to an acute stressful episode does however seem to enhance the capacity of the hippocampus to exhibit LTD in vivo in male animals. In the present experiments, we examined the capacity for low-frequency stimuli (low-frequency stimulation (LFS)) to induce LTD in juvenile male and female animals following an acute stress episode. Interestingly, prior exposure to stress was only required for the induction of LTD in male animals, while both control and stressed female animals exhibited equivalent LTD. In animals that were exposed to ethanol in utero, a similar requirement for prior exposure to stress to elicit LTD was found for male, but not female animals. This prenatal ethanol exposure did not in itself alter the capacity for LTD induction in either sex; however, in utero food restriction did enhance LTD induction in both male and female animals, irrespective of whether they were exposed to stress just prior to being administered LFS. These results indicate that in utero dietary restriction more drastically affects CA1 LTD than in utero ethanol exposure. In addition, female animals seem to exhibit LTD in vivo in the absence of stress much more easily than their male counterparts.

Acute and chronic dose of alcohol affect the load carrying capacity of long bone in rats

In the present investigation, the effects of acute and chronic dose of alcohol were evaluated on mechanical properties of long bones of Sprague Dawley rats. In "acute study", 18 animals were divided into three groups containing six animals each, i.e. Group A: control animals, normal saline was given to them intraperitoneally for the period of 5 days; Group B: treated animals, given 20% (v/v) absolute alcohol and Group C: treated animals, given 30% (v/v) absolute alcohol, by same route and time duration. In "chronic study", also, 18 animals were divided into three groups containing six animals each, i.e. Group A: control animals, normal saline was given to them intraperitoneally for the period of 6 weeks; Group B: treated animals, given 20% (v/v) absolute alcohol and Group C: treated animals, given 30% (v/v) absolute alcohol by same route and time duration. A significant increase was observed in bone weight of animals taking 20% alcohol but there was decrease in the same for 30% alcohol in case of acute study. For chronic study, there was a decrease in bone weight for both treated groups. During acute study, breaking strength of bone was increased in case of 20% alcohol administration but a slight decrease was shown in the same for 30% alcohol group as compared to control animals. Breaking strength of long bone in the case of chronic study was decreased in case of both groups taking alcohol, i.e. 20% and 30%. The present document is useful in understanding the functional load carrying capacity of bone during alcoholism.

Prenatal ethanol exposure disrupts the histological stages of fetal bone development

Maternal ethanol intake during pregnancy results in impairments in general growth and skeletal development in the offspring. We have previously shown that ethanol retards skeletal ossification at doses lower than those that affect growth. Moreover, skeletal sites vary in their sensitivity to ethanol effects, with more severe effects occurring in bones that undergo a greater proportion of their development in utero. Taken together, these data suggest that ethanol has specific effects on bone development, and that later stages in the ossification process may be particularly affected. Such effects could have important implications for the offspring's long-term bone health, as studies suggest that the intrauterine environment can program the skeleton. The present study examined the histological stages of bone development to determine if prenatal ethanol exposure alters the morphological development of the growth plate in the fetal rat. Rats were fed a liquid diet containing ethanol (Ethanol, E group), or without ethanol (Pair-Fed, PF, or Control, C groups) for 6 weeks: 3 weeks prior to breeding and during 3 weeks of pregnancy. Fetal tibiae were fixed, decalcified and stained for histological analysis on day 21 of gestation. Maternal ethanol intake resulted in a significant decrease in fetal total bone and diaphysis lengths, compared with tibiae from PF and C fetuses. Although the lengths of the epiphyses were not affected, ethanol disrupted the organization of the histological zones within the epiphyses. Prenatal ethanol exposure decreased the length of the resting zone, but increased the length of the hypertrophic zone. Enlargement of the hypertrophic zone is consistent with an effect of ethanol on the later stages of bone development; however, ethanol's effect on the resting zone indicates that earlier stages of bone development may also be disrupted. The functional significance of these morphological changes to long-term bone health remains to be determined.

Effect of Chronic Ethanol Consumption on the Response of Parathyroid Hormone to Hypocalcemia in the Pregnant Rat

BACKGROUND

Chronic alcohol (ethanol) consumption during pregnancy results in maternal/fetal hypocalcemia, which may underlie some of ethanol's adverse effects on maternal and fetal bone, and fetal/neonatal health. Ethanol appears to alter the relationship between parathyroid hormone (PTH) and blood calcium (Ca) level, and PTH does not increase in response to ethanol-induced hypocalcemia. However, it is not known whether ethanol actually prevents PTH from responding, or whether the ability to regulate blood Ca is intact, but ethanol lowers the level of Ca maintained. The objective of this study was to determine whether chronic ethanol consumption impairs the ability of the pregnant female to increase PTH in response to acute hypocalcemia.

METHODS

Rats were fed isocaloric diets with ethanol (36% ethanol-derived calories, E group) or without ethanol [pair-fed (PF) and control (C) groups], before and throughout 21 days of gestation. On day 21 gestation, rats received an intraperitoneal injection of ethylene glycol-bis (beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) (300 or 500 mumol/kg body weight) or saline (saline group), or no injection (baseline group). Blood was collected from the baseline group, and at 30 or 60 minutes postinjection (saline and EGTA groups), and analyzed for ionized Ca (iCa), pH, and PTH.

RESULTS

Consistent with previous studies, ethanol consumption decreased blood iCa levels at baseline, but PTH levels did not differ among groups. Administration of EGTA significantly decreased blood iCa levels by 30 minutes, but ethanol did not prevent PTH from increasing in response to the hypocalcemia. In all diet groups, PTH levels were significantly increased by 30 minutes. Ethanol did, however, appear to decrease the maximum PTH level achievable in blood.

CONCLUSIONS

These data suggest that chronic ethanol consumption does not impair the ability of the pregnant rat to raise serum PTH levels in response to acute hypocalcemia, but ethanol's effect on maximal PTH secretion could impair the ability of the pregnant female to sustain high PTH levels in response to chronic hypocalcemia.

Hippocampal cell proliferation is reduced following prenatal ethanol exposure but can be rescued with voluntary exercise

The ingestion of ethanol during pregnancy has a number of deleterious consequences for the unborn offspring, producing structural and functional deficits that affect the brain and many other organs into adulthood. The hippocampus is a brain area that is particularly sensitive to ethanol's adverse effects. In a previous study we showed that voluntary exercise can ameliorate deficits in long-term potentiation and behavior that occur following prenatal ethanol exposure (Eur J Neurosci, 2005, 21, 1719-1726). In the present study, we investigated the effects of prenatal ethanol exposure on neurogenesis in adulthood, and tested the hypothesis that voluntary exercise would ameliorate any deficits observed. Sprague-Dawley females were administered one of three diets throughout gestation: (i) ethanol (E), a liquid diet containing 36.5% ethanol-derived calories; (ii) pair-fed (PF), a liquid control diet, with maltose-dextrin isocalorically substituted for ethanol, in the amount consumed by an E partner (g/kg body wt/day of gestation); and (iii) ad-libitum-fed control (C), normal laboratory chow and water, ad libitum. The offspring were housed individually at postnatal day (PND) 35, and at PND 50 were randomly assigned to cages either with or without an exercise wheel. BrdU (200 mg/kg, I.P.) was injected on PND 57, and animals terminated either 24 h (proliferation) or 4 weeks (neurogenesis) later. Our results demonstrate that prenatal ethanol exposure significantly decreases both cell proliferation and neurogenesis in the adult dentate gyrus. Animals in the PF condition also showed reduced neurogenesis. In contrast, all animals that engaged in voluntary exercise showed a significant increase in cell proliferation and neurogenesis. These results indicate that prenatal ethanol exposure can suppress both cell proliferation and neurogenesis, and that these effects may be, at least in part, nutritionally mediated. Importantly, voluntary exercise appears to have beneficial effects for these long-lasting deficits in hippocampal volume and cell number that have been observed in animals exposed to ethanol in utero.

Binge alcohol exposure during all three trimesters alters bone strength and growth in fetal sheep

Women who drink while pregnant are at a high risk of giving birth to children with neurodevelopmental disorders. Heavy consumption of alcohol during pregnancy is also known to be deleterious to fetal bone growth in both humans and laboratory animals. However, nothing is known regarding the effect of maternal moderate and heavy alcohol binging on fetal and maternal bone strength. The purpose of this study was to determine the effects of moderate and heavy alcohol binging throughout gestation on fetal and maternal bone growth and strength. The study was conducted using an ovine model system. The large body mass of the ovine fetus, the longer gestation that is more similar to that of humans, and the fact that all three trimester equivalents occur in utero, make the sheep an excellent model for studying Fetal Alcohol Spectrum Disorder. Suffolk ewes were mated and, beginning on gestational day 4, received intravenous infusions over 1 h on 3 consecutive days per week followed by 4 days without treatment concluding on day 132 of pregnancy. Pregnant ewes were divided into four groups: two alcohol treatment groups (0.75 and 1.75 g/kg of body weight), one pair-fed saline control group, and an untreated normal control group. The fetuses were harvested on gestational day 133. Maternal and fetal femoral and tibial dimensions were measured and the maximum strength (MPa) carried by the bone tissue was determined using a three-point bending procedure. Maternal bones were not different among groups. The higher alcohol dose resulted in reduced fetal femoral bone strength, whereas the tibial bone strength was lower when compared with the normal control subjects. In contrast, the lower alcohol dose increased fetal femoral strength compared to the normal control subjects. The alcohol-exposed fetal bones also tended to exhibit reduced lengths. We conclude that binge alcohol exposure throughout gestation resulted in dose-dependent differences in the maximum stress absorbed by the fetal bones.

Ethanol administration results in a prolonged decrease in blood ionized calcium levels in the rat

Previous studies have shown that ethanol decreases the level of ionized calcium (iCa) in the blood, and appears to prevent a compensatory increase in parathyroid hormone level. We have shown, however, that the presence of ethanol interferes with the measurement of blood iCa by the most commonly used iCa analyzer. It is impossible to interpret ethanol-induced alterations in Ca-regulating hormone levels without accurate measurement of blood iCa, thus the purpose of this study was to determine if ethanol decreases blood iCa levels independent of methodological artifacts. The time course of ethanol's effect and the relationship between iCa and blood ethanol concentration (BEC) were also examined. Rats (n=22) received ethanol (1.5 or 3 g/kg body weight) or saline by intraperitoneal injection. Blood samples were obtained by tail nick at 0, 2, 6, 24, 48 h and 8 days postinjection, and analyzed for iCa, pH, and BEC. Blood iCa and pH were measured using the I-Stat Clinical Analyzer, whose performance is not affected by the presence of ethanol. Ethanol administration resulted in a decrease in blood iCa levels. The magnitude and time course of the decrease varied with dose of ethanol, being greater and more prolonged with the higher dose, and blood iCa levels were not fully recovered at 48 h postinjection. No significant relationship was found between individual iCa and BEC values. This study confirms that ethanol decreases blood iCa levels, independent of methodological artifacts. Prolonged disruptions in Ca homeostasis resulting from ethanol consumption could have implications for long-term bone health.

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.

Voluntary exercise rescues deficits in spatial memory and long-term potentiation in prenatal ethanol-exposed male rats

Prenatal ethanol exposure can lead to long-lasting impairments in the ability to process spatial information in rats, as well as produce long-lasting deficits in the ability of animals to exhibit long-term potentiation, a biological model of learning and memory processing. Conversely, we have recently shown that both spatial memory and long-term potentiation can be enhanced in animals that are given access to a running wheel in their home cage. In the present study, Sprague-Dawley rat dams were given one of three diets throughout gestation: (i) a liquid diet containing ethanol (35.5% ethanol-derived calories); (ii) a liquid diet, isocaloric to the ethanol diet, but with maltose-dextrin substituting for the ethanol derived calories and (iii) an ad libitum diet of standard rat chow. At weaning (28 days) animals were housed individually in either a standard rat cage, or a cage that contained a running wheel. Adult offspring were tested on a two trial version of the Morris water maze beginning at postnatal day 60, for five consecutive days. Following this, the capacity of the perforant path to dentate gyrus pathway to sustain long-term potentiation was examined in these animals using theta-patterned conditioning stimuli. Our results demonstrate that prenatal ethanol exposure can produce pronounced deficits in both spatial memory and long-term potentiation, but that allowing animal's access to voluntary exercise can attenuate these deficits to the point that those exposed to ethanol prenatally can no longer be differentiated from control animals. These findings indicate that voluntary exercise may have therapeutic benefits for individuals that have undergone prenatal ethanol exposure.