Acute effects of ethanol on mineral metabolism and trabecular bone in Sprague-Dawley rats

Six months of voluntary alcohol consumption in male cynomolgus macaques reduces intracortical bone porosity without altering mineralization or mechanical properties

Chronic heavy alcohol consumption is a risk factor for low trauma bone fracture. Using a non-human primate model of voluntary alcohol consumption, we investigated the effects of 6 months of ethanol intake on cortical bone in cynomolgus macaques (Macaca fascicularis). Young adult (6.4 ± 0.1 years old, mean ± SE) male cynomolgus macaques (n = 17) were subjected to a 4-month graded ethanol induction period, followed by voluntary self-administration of water or ethanol (4 % w/v) for 22 h/d, 7 d/wk. for 6 months. Control animals (n = 6) consumed an isocaloric maltose-dextrin solution. Tibial response was evaluated using densitometry, microcomputed tomography, histomorphometry, biomechanical testing, and Raman spectroscopy. Global bone response was evaluated using biochemical markers of bone turnover. Monkeys in the ethanol group consumed an average of 2.3 ± 0.2 g/kg/d ethanol resulting in a blood ethanol concentration of 90 ± 12 mg/dl in longitudinal samples taken 7 h after the daily session began. Ethanol consumption had no effect on tibia length, mass, density, mechanical properties, or mineralization (p > 0.642). However, compared to controls, ethanol intake resulted in a dose-dependent reduction in intracortical bone porosity (Spearman rank correlation = -0.770; p < 0.0001) and compared to baseline, a strong tendency (p = 0.058) for lower plasma CTX, a biochemical marker of global bone resorption. These findings are important because suppressed cortical bone remodeling can result in a decrease in bone quality. In conclusion, intracortical bone porosity was reduced to subnormal values 6 months following initiation of voluntary ethanol consumption but other measures of tibia architecture, mineralization, or mechanics were not altered.

Binge Ethanol Exposure in Mice Represses Expression of Genes Involved in Osteoblast Function and Induces Expression of Genes Involved in Osteoclast Differentiation Independently of Endogenous Catalase

Excessive ethanol consumption is a risk factor for osteopenia. Since a previous study showed that transgenic female mice with overexpression of catalase are partially protected from ethanol-mediated trabecular bone loss, we investigated the role of endogenous catalase in skeletal ethanol toxicity comparing catalase knockout to wild-type mice. We hypothesized that catalase depletion would exacerbate ethanol effects. The mice were tested in a newly designed binge ethanol model, in which 12-week-old mice were exposed to 4 consecutive days of gavage with ethanol at 3, 3, 4, and 4.5 g ethanol/kg body weight. Binge ethanol decreased the concentration of serum osteocalcin, a marker of bone formation. The catalase genotype did not affect the osteocalcin levels. RNA sequencing of femoral shaft RNA from males was conducted. Ethanol exposure led to significant downregulation of genes expressed in cells of the osteoblastic lineage with a role in osteoblastic function and collagen synthesis, including the genes encoding major structural bone proteins. Binge ethanol further induced a smaller set of genes with a role in osteoclastic differentiation. Catalase depletion affected genes with expression in erythroblasts and erythrocytes. There was no clear interaction between binge ethanol and the catalase genotype. In an independent experiment, we confirmed that the binge ethanol effects on gene expression were reproducible and occurred throughout the skeleton in males. In conclusion, the binge ethanol exposure, independently of endogenous catalase, reduces expression of genes involved in osteoblastic function and induces expression of genes involved in osteoclast differentiation throughout the skeleton in males.

Impact of Alcohol on Bone Health, Homeostasis and Fracture repair

Purpose of review

Alcohol use continues to rise globally. We review the current literature on the effect of alcohol on bone health, homeostasis and fracture repair to highlight what has been learned in people and animal models of alcohol consumption.

Recent findings

Recently, forkhead box O (FoxO) has been found to be upregulated and activated in mesenchymal stem cells (MSC) exposed to alcohol. FoxO has also been found to modulate Wnt/β-catenin signaling, which is necessary for MSC differentiation. Recent evidence suggests alcohol activates FoxO signaling, which may be dysregulating Wnt/β-catenin signaling in MSCs cultured in alcohol.

Summary

This review highlights the negative health effects learned from people and chronic and episodic binge alcohol consumption animal models. Studies using chronic alcohol exposure or alcohol exposure then bone fracture repair model have explored several different cellular and molecular signaling pathways important for bone homeostasis and fracture repair, and offer potential for future experiments to explore additional signaling pathways that may be dysregulated by alcohol exposure.

Hypocalcaemia, alcohol drinking and viroimmune responses in ART recipients

Metabolic perturbations associated with HIV and antiretroviral therapies are widespread. Unfortunately, research has predominantly focused in cardiometabolic problems, neglecting other important areas. In fact, the immune-calcium-skeletal interface has been understudied despite its potential relevance in people living with HIV (PLWH). Using a case-control methodology, 200 PLWH receiving medical care were enrolled and stratified according to hazardous vs. non-hazardous alcohol intake (HAU vs. non-HAU) and calcium (Ca) levels by analyzing baseline data. The group was chosen to represent relatively "pure" HAU with minimal drug use and no psychiatric diagnoses. With these narrow parameters in place, we found evidence that HAU significantly increases TNF-α levels compared to Non-HAU (2.8 ± 0.6 vs. 1.9 ± 0.3 pg/ml, p = 0.05) and decreases blood Ca levels (9 ± 0.6 vs. 9.4 ± 0.5, p = 0.03). Our analyses also suggest that chronic inflammation, as indicated by increased TNF-α levels, is associated with hypocalcemia (hypoCa <8.6). Despite the limited prevalence of hypoCa, these findings are clinically significant given that hypoCA PLWH exhibited decreased CD4 (253 ± 224 vs. 417.7 ± 281, p = 0.02), B cells (147 ± 58 vs. 248 ± 151, p = 0.03) and NK cells (146.8 ± 90 vs. 229 ± 148, p = 0.008) and elevated CD8 (902.5 ± 438 vs. 699 ± 510, p = 0.09) compared to those with normal calcium. Furthermore, calcium effects on viral load were also evident with hypoCA exhibiting the highest loads (140,187 ± 111 vs. 35,622 ± 7770 HIV copies, p = 0.01). Multivariate analyses confirmed the significance of hypoCa in predicting viroimmune parameters. This paper provides the first evidence that hypoCa accounts for some of the variation in viroimmune measures in HAART recipients and suggests that hypoCa may be mediating alcohol's deleterious effects.

Effects of ethanol on the osteogenesis around porous hydroxyapatite implants

Alcohol consumption compromises bone tissue, and thus may either impair or stop the fixation and maintenance of osseointegrated implants. To evaluate the effects of 5% and 15% ethanol on bone neoformation around porous hydroxiapatite implants. Fifteen rats were separated into 3 groups of 5 animals each: control (CT); 5% alcohol (A); and 15% alcohol (AA). After four weeks of ethanol consumption, the rats received porous hydroxiapatite implants into surgically made cavities in the femur. After surgery, the animals continued to consume ethanol until day 90 of the experiment, when they were euthanised and their femurs removed for histological processing. Bone tissue was found around the ceramic specimens of all the animals. The largest volume of neoformed bone around ceramic specimens occurred in the CT group, and the smallest in the AA group, followed by the A group. It was concluded that ethanol consumption produced a negative effect on osteogenesis around hydroxyapatite implants. Even small doses, such as the 5% ethanol dilution can interfere with bone repair.

Efeitos do alcoolismo e da desintoxicação alcoólica sobre o reparo e biomecânica óssea

OBJETIVO: Avaliar os efeitos do consumo crônico de etanol e da desintoxicação alcoólica sobre a resistência mecânica do osso e neoformação óssea junto a implantes de hidroxiapatita densa (HAD) realizados em ratos. MÉTODOS: Foram utilizados 15 ratos divididos em três grupos, sendo controle (CT), alcoolista crônico (AC) e desintoxicado (DE). Após quatro semanas, foi realizada implantação de HAD na tíbia e produzida falha no osso parietal, em seguida o grupo AC continuaram a consumir etanol e o grupo DE iniciaram a desintoxicação. Ao completar 13 semanas os animais sofreram eutanásia, os ossos foram coletados para o processamento histomorfométrico e os fêmures encaminhados ao teste mecânico de resistência. RESULTADOS: Os animais do grupo AC apresentaram menores valores de neoformação óssea, de calcemia e resistência mecânica, quando comparado aos grupos CT e DE. Os animais dos grupos DE apresentaram valores superiores em todas as variáveis avaliadas em relação ao grupo AC. CONCLUSÃO: O consumo de etanol interferiu na osteogênese ao redor de implante de HAD, nos níveis de cálcio e na resistência mecânica óssea. A desintoxicação alcoólica se mostrou eficaz, pois aumentou à osteogênese e osseointegração da HAD, a calcemia e resistência mecânica óssea. Nivel de Evidência I, estudo terapeutico.

Sex-dependent alterations in erythrocyte trace element levels and antioxidant status after a month of moderate daily red wine consumption

OBJECTIVE

We tested the hypothesis whether trace elements and antioxidant status change in a sex-dependent manner may contribute to sex-dependent hepatic effects of moderate daily wine consumption.

PATIENT AND METHODS

Twenty-one healthy young men and women were enrolled to this study who consumed red wine 0.3 and 0.2 l per day, respectively, for a month. Blood was taken at baseline (BV) and at end of the study (EV). Red cell trace element levels, red cell and plasma antioxidant status and serum routine blood chemistry were assessed at baseline and at the end of the study.

RESULTS

No sign of hepatotoxicity was detected. BV level of some trace elements (i.e. Zn, Pb) and Zn/Cu ratios were higher in women than in men. Ca, Mg, Pb, Sr and Zn levels and the Zn/Cu ratio had lower EV than BV in women. In men, Al, Ca, Li, Pb and Sr levels had lower EV than BV. The tested antioxidant parameters improved in both the sexes.

CONCLUSION

Although no hepatotoxicity was observed, changes in trace element content were detected after 1 month of moderate red wine consumption. The most remarkable sex-specific alteration was the decrease of Zn levels and of the Zn/Cu ratio in women. Given the protective effect of Zn against liver damage, this finding suggests a possible contribution of decreased Zn levels to sex-dependent effects of red wine.

Effects of alcohol and nicotine on the mechanical resistance of bone and bone neoformation around hydroxyapatite implants

The consumption of alcohol or nicotine is harmful to the integrity of bone tissue, hindering or even impeding the fixation and maintenance of bone implants. The aim of the present work was to evaluate the effects of ethanol and nicotine, when consumed alone and simultaneously, on both bone mechanical resistance and bone neoformation around hydroxyapatite implants. Twenty rats were divided into four groups: control (CT), alcohol (A), nicotine (N) and nicotine + alcohol (N + A). After 4 weeks of alcohol and/or nicotine consumption, dense (HAD) and porous (HAP) bodies were respectively implanted in a surgically produced bone defect in the right and left tibiae. After the surgeries, the animals continued to consume alcohol and/or nicotine. After ninety days, the animals were sacrificed and the tibiae and femurs were isolated for histological processing and mechanical assays. All the animals presented newly formed bone tissue close to the HAD and HAP ceramic bodies. The animals of the N + A group presented a smaller volume of neoformed bone. Group A animals presented smaller bone volume around the implants in relation to the animals from group N. Bone resistance to mechanical loads was smallest in animals from the N + A group, followed (in order) by the A and N groups. Thus, it can be concluded that nicotine or alcohol consumption produced negative effects on bone mechanical resistance and on the osteogenesis around the HAD and HAP implants. In addition, the simultaneous consumption of the two substances intensified their harmful effects.

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.

Intermittent exposure to ethanol vapor affects osteoblast behaviour more severely than estrogen deficiency does in vitro study on rat osteoblasts

With rising rates of alcohol consumption acute and chronic damage from alcohol is expected to increase all over the world. Habitual excessive alcohol consumption is associated with pathological effects on bone. The aim of the present in vitro study was to investigate comparatively the proliferation and synthetic activity of osteoblasts (OB) isolated from the trabecular bone of rats previously exposed to 7-week intermittent exposure to ethanol vapor, sham-aged rats and long-term estrogen deficient rats. Cell proliferation (WST1) and synthesis of alkaline phosphatase (ALP), osteocalcin (OC), collagen I (CICP), transforming growth factor beta1 (TGF-beta1), interleukin-6 (IL-6), tumor necrosis factor alfa (TNFalpha) were measured at 3, 7 and 14 days of culture. Osteoblast proliferation rate and TGF-beta1, IL-6 and TNFalpha syntheses were significantly affected by alcohol exposure. Estrogen deficiency and alcohol consumption share many common pathophysiological mechanisms of damage to bone, but alcohol affects OB proliferation and TNFalpha synthesis significantly more than menopause does. Therefore, these in vitro data suggest that alcohol has even more deleterious effects on bone than estrogen deficiency does.

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.

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.

Inhibition of bone repair in a rat model for chronic and excessive alcohol consumption

Alcohol abuse is associated with increases in both the incidence of fractures and complications in fracture healing. The purpose of this study was to determine the dose-dependent effects of ethanol on bone repair in a rat model. Three-month-old male Wistar rats were continuously fed liquid diets containing ethanol as either 36% or 26% of total calories or control diets for 6 weeks. Then, a bone repair model was created in all rats. Bone healing and liver metabolism were evaluated 7 weeks after bone injury. For each dose, there were three ethanol-feeding groups receiving (1) ethanol for 13 weeks, (2) control diet for 13 weeks (pair-fed), and (3) ethanol before bone injury and control diet (pair-fed) after injury. Another group was fed ethanol (36%) before injury and given control diet ad libitum after injury. There were also two nutritional controls consuming control diet and standard rat chow ad libitum for 13 weeks. Abnormal liver metabolism was evident at the higher ethanol dose - increases in cytochrome P4502E1 specific activity (5-fold; P < .01), triglyceride content (4-fold; P < .02), and liver weight (25%; P = .05) - compared with pair-fed controls. The higher dose of ethanol resulted in deficient bone repair when compared with rats receiving ethanol-free control diet by pair-feeding: 26% less (P = .02) rigidity of the repaired bone, 41% less (P = .02) intrinsic stiffness, 24% less intrinsic strength (P = .05), and 14% less (P = .001) ash density of the repair tissue. The reduced food consumption of ethanol-fed rats compared with that in the nutritional controls did not contribute to this deficiency. Furthermore, removal of ethanol (as 36% of calories) from the diet after bone injury completely restored normal bone healing and nearly normalized the liver metabolism. The lower ethanol dose (26% of calories) had a minimal effect on liver metabolism and bone repair. We conclude that ethanol (as 36% of calories) in the rat diet, especially during the postinjury period, was solely responsible for the observed inhibition of bone repair.

Subperiosteal hydroxyapatite implants in rats submitted to ethanol ingestion

It has been reported that excessive alcohol consumption can contribute to failures on the osteointegration process in the site of implantation. Hydroxyapatite blocks were implanted under the periosteum of the femur and skull of 40 rats divided into two groups of 20 animals, one of them received 25% ethanol diluted in water and the other did not. Bone formation close to the hydroxyapatite implant was observed in the femur of all animals 2 weeks after surgery, however the bone volume was lower in ethanol-treated animals. It was observed in the skulls of the ethanol-treated animals a delay in new bone formation process, as a lower bone volume, too. After 4 weeks of the implantation, just one ethanol-treated animal showed no new bone formation in the femur, while no bone formation was observed in the skulls of two other rats. On the 8th and 16th weeks, bone formation was observed in both femur and skull from both groups, although always with less volume in ethanol-treated rats. We concluded that ethanol consumption did not impair osteointegration of ceramic implants, but it might have reduced the osteogenic capacity of periosteal cells in the femur and parietal bone of the rats.

Ethanol interferes with the measurement of extracellular ionized calcium

BACKGROUND

Maintenance of extracellular calcium (Ca) concentration within narrow limits is critical for normal cell function and optimization of bone health. Ionized Ca (iCa), the form of Ca that is regulated, has been reported to vary inversely with blood alcohol concentration (BAC). The mechanism by which ethanol decreases blood iCa levels is unknown. However, one possible explanation is that it is, at least partially, a methodological artifact due to an effect of ethanol on the function of the ion selective electrode used to measure iCa. The purpose of this study was to determine if ethanol interferes with the measurement of iCa and if this interference can account for the typically observed in vivo effects of ethanol consumption on blood iCa levels.

METHODS

Ethanol (0-5 microl/ml) was added to blood or iCa standards and the iCa concentration measured using the ICA2 iCa analyzer (Radiometer) or the I-Stat Clinical Analyzer (Abbott Laboratories). Both instruments use an ion selective electrode to measure iCa. The relationship between iCa and BAC determined from the ex vivo addition of ethanol to blood was compared with relationships obtained in vivo during chronic ethanol consumption.

RESULTS

Addition of ethanol to blood or iCa standards resulted in a dose-dependent decrease in iCa concentration when iCa was measured using the ICA2 analyzer but had no effect on iCa concentration when measured with the I-Stat Clinical Analyzer. Ethanol's effect on iCa with the ICA2 analyzer did not differ between blood and standards, and ethanol had no effect on pH, suggesting that the ethanol-induced decrease in iCa was due to a methodological artifact. However, the magnitude of ethanol's effect was small and does not account entirely for the relationship between iCa and BAC observed in vivo with chronic ethanol consumption.

CONCLUSION

Ethanol can interfere with the measurement of iCa using ion selective electrodes, but this interference depends on the analyzer used. This is a significant methodological issue that has largely been unrecognized in the field of alcohol research. Although this interference does not explain entirely the relationship between iCa and BAC observed in vivo in studies on chronic ethanol consumption, it complicates investigations designed to assess the effect of ethanol on Ca homeostasis.

Effect of Duration of Alcohol Consumption on Calcium and Bone Metabolism During Pregnancy in the Rat

BACKGROUND

Little is known about the consequences of drinking during pregnancy for the long-term health of the mother. Alcohol (ethanol) has been shown to disrupt calcium (Ca) homeostasis and is known to have deleterious effects on bone. During pregnancy, bone turnover is increased to maintain Ca homeostasis; therefore, pregnancy may be a time of life when maternal bone is particularly susceptible to the effects of ethanol. This study investigated the effect of duration of ethanol consumption on Ca homeostasis and bone during pregnancy in the rat.

METHODS

Rats were fed ethanol (36% ethanol-derived calories) in liquid diets for 3 (21 days gestation only) or 6 (3 weeks before and throughout 21 days gestation) weeks. Maternal blood was analyzed for Ca (total and ionized Ca [iCa]), the Ca-regulating hormones (parathyroid hormone [PTH], 1,25(OH)2D, calcitonin), and osteocalcin (a marker for bone formation). Bone was analyzed for ash (mineral) content.

RESULTS

Dams consuming ethanol (E dams) had decreased blood Ca levels (total and iCa) at both 3 and 6 weeks, but iCa was lower in E dams after 6 compared with 3 weeks. Importantly, ethanol seemed to interfere with the normal compensatory response to these decreased Ca levels. In contrast to pair-fed controls, serum PTH levels actually were decreased, 1,25(OH)2D levels failed to increase, and calcitonin levels were increased in ethanol-consuming dams, regardless of duration. Moreover, ethanol decreased bone formation, as indicated by serum osteocalcin levels, after both 3 and 6 weeks consumption, and after 6 weeks, the ash content of bone also was decreased. In addition, a relationship was found between the blood alcohol concentration (BAC) and some measures of Ca and bone metabolism. Serum 1,25(OH)2D and osteocalcin levels varied inversely, whereas serum calcitonin varied directly with BAC, suggesting that time of sampling after drinking may be an important variable for interpreting ethanol's effects on Ca and bone metabolism. In all rats, serum osteocalcin levels varied directly with PTH and 1,25(OH)2D levels.

CONCLUSIONS

Ethanol consumption during pregnancy impaired Ca homeostasis in the dam, regardless of duration of consumption, and resulted in decreased bone formation and ash content of bone. Significant relationships among the Ca-regulating hormones, BAC, and osteocalcin support the hypothesis that ethanol's effects on the Ca-regulating hormones may mediate some of its effects on bone.

Spine bone mineral density and vertebral body height are altered by alcohol consumption in growing male and female rats

Alcohol, consumed for extended periods by growing male and female rats, impairs osteogenesis and reduces bone size and mass. The skeletal sites of experimental animals commonly chosen for an evaluation of bone mechanical characteristics and architectural properties, bone matrix gene expression, tissue concentrations of growth factors, and bone mineral density (BMD) have been the tibiae and femora. Far less attention has been focused on the spine and the effects of alcohol on vertebral BMD and vertebral body height. Fifteen male and 15 female Sprague-Dawley rats (aged 30 days) were divided into three groups: an alcohol-fed group, matched to a pair-fed non-alcohol isocaloric-fed control group with animals of the same sex, and an ad libitum-fed control group. Alcohol-fed animals received a Lieber-DeCarli liquid diet containing 36% of caloric intake as alcohol; isocaloric pair-fed rats received the same diet without alcohol. After 45 days of feeding, the lumbar spine was removed. The fourth lumbar vertebra from each spine was dissected, and the vertebral body height was measured. Lumbar vertebral body height was significantly reduced by alcohol consumption in both male and female rats compared with findings for either control group. Cancellous and cortical BMD of the vertebral body was determined by peripheral quantitative computed tomography (pQCT). Male and female rats (aged 75 days) in the ad libitum-fed group had similar vertebral body cortical and cancellous BMD, with cortical BMD being greater than cancellous BMD. Lumbar vertebral body cancellous and cortical BMD declined for both male and female rats in response to alcohol consumption for 45 days compared with findings for either control group. More BMD loss occurred from cancellous than from cortical bone in both sexes after chronic alcohol consumption. Chronic alcohol consumption by growing rats results in vertebral growth reduction and vertebral osteopenia.