Alcohol-fed Groups Research Articles

PDE5 inhibitor sildenafil attenuates cardiac microRNA 214 upregulation and pro-apoptotic signaling after chronic alcohol ingestion in mice.

Abusive chronic alcohol consumption can cause metabolic and functional derangements in the heart and is a risk factor for development of non-ischemic cardiomyopathy. microRNA 214 (miR-214) is a molecular sensor of stress signals that negatively impacts cell survival. Considering cardioprotective and microRNA modulatory effects of sildenafil, a phosphodiesterase 5 (PDE5) inhibitor, we investigated the impact of chronic alcohol consumption on cardiac expression of miR-214 and its anti-apoptotic protein target, Bcl-2 and whether sildenafil attenuates such changes. Adult male FVB mice received unlimited access to either normal liquid diet (control), alcohol diet (35% daily calories intake), or alcohol + sildenafil (1mg/kg/day, p.o.) for 14weeks (n = 6-7/group). The alcohol-fed groups with or without sildenafil had increased total diet consumption and lower body weight as compared with controls. Echocardiography-assessed left ventricular function was unaltered by 14-week alcohol intake. Alcohol-fed group had 2.6-fold increase in miR-214 and significant decrease in Bcl-2 expression, along with enhanced phosphorylation of ERK1/2 and cleavage of PARP (marker of apoptotic DNA damage) in the heart. Co-ingestion with sildenafil blunted the alcohol-induced increase in miR-214, ERK1/2 phosphorylation, and maintained Bcl-2 and decreased PARP cleavage levels. In conclusion, chronic alcohol consumption triggers miR-214-mediated pro-apoptotic signaling in the heart, which was prevented by co-treatment with sildenafil. Thus, PDE5 inhibition may serve as a novel protective strategy against cardiac apoptosis due to chronic alcohol abuse.

Iron Supplementation Reverses the Reduction of Hydroxymethylcytosine in Hepatic DNA Associated With Chronic Alcohol Consumption in Rats.

BackgroundAlcohol is known to affect two epigenetic phenomena, DNA methylation and DNA hydroxymethylation, and iron is a cofactor of ten-eleven translocation (TET) enzymes that catalyze the conversion from methylcytosine to hydroxymethylcytosine. In the present study we aimed to determine the effects of alcohol on DNA hydroxymethylation and further effects of iron on alcohol associated epigenetic changes.MethodsTwenty-four male Sprague-Dawley rats were fed either Lieber-DeCarli alcohol diet (36% calories from ethanol) or Lieber-DeCarli control diet along with or without iron supplementation (0.6% carbonyl iron) for 8 weeks. Hepatic non-heme iron concentrations were measured by colorimetric assays. Protein levels of hepatic ferritin and transferrin receptor were determined by Western blotting. Methylcytosine, hydroxymethylcytosine and unmodified cytosine in DNA were simultaneously measured by liquid chromatography/mass spectrometry method.ResultsIron supplementation significantly increased hepatic non-heme iron contents (P < 0.05) but alcohol alone did not. However, both alcohol and iron significantly increased hepatic ferritin levels and decreased hepatic transferrin receptor levels (P < 0.05). Alcohol reduced hepatic DNA hydroxymethylation (0.21% ± 0.04% vs. 0.33% ± 0.04%, P = 0.01) compared to control, while iron supplementation to alcohol diet did not change DNA hydroxymethylation. There was no significant difference in methylcytosine levels, while unmodified cytosine levels were significantly increased in alcohol-fed groups compared to control (95.61% ± 0.08% vs. 95.26% ± 0.12%, P = 0.03), suggesting that alcohol further increases the conversion from hydroxymethylcytosine to unmodified cytosine.ConclusionsChronic alcohol consumption alters global DNA hydroxymethylation in the liver but iron supplementation reverses the epigenetic effect of alcohol.

Saturated and Unsaturated Dietary Fats Differentially Modulate Ethanol-Induced Changes in Gut Microbiome and Metabolome in a Mouse Model of Alcoholic Liver Disease

Alcoholic liver disease (ALD) ranks among major causes of morbidity and mortality. Diet and crosstalk between the gut and liver are important determinants of ALD. We evaluated the effects of different types of dietary fat and ethanol on the gut microbiota composition and metabolic activity and the effect of these changes on liver injury in ALD. Compared with ethanol and a saturated fat diet (medium chain triglycerides enriched), an unsaturated fat diet (corn oil enriched) exacerbated ethanol-induced endotoxemia, liver steatosis, and injury. Major alterations in gut microbiota, including a reduction in Bacteroidetes and an increase in Proteobacteria and Actinobacteria, were seen in animals fed an unsaturated fat diet and ethanol but not a saturated fat diet and ethanol. Compared with a saturated fat diet and ethanol, an unsaturated fat diet and ethanol caused major fecal metabolomic changes. Moreover, a decrease in certain fecal amino acids was noted in both alcohol-fed groups. These data support an important role of dietary lipids in ALD pathogenesis and provide insight into mechanisms of ALD development. A diet enriched in unsaturated fats enhanced alcohol-induced liver injury and caused major fecal metagenomic and metabolomic changes that may play an etiologic role in observed liver injury. Dietary lipids can potentially serve as inexpensive interventions for the prevention and treatment of ALD.

A Mechanism for Inhaled Anesthetic-Induced Solid Organ Injury: Inflammation

Background: Inhaled anesthetics, including halothane, iso- and sevoflurane induce proinflammatory cytokine release. Halothane is an inhaled anesthetic agent that is metabolized by the liver into a highly reactive product, trifluoroacetyl chloride, which can react endogenously to form a trifluoroacetyl-adduct (TFA-adduct). The MAA-adduct is formed by acetaldehyde and malondialdehyde reacting with endogenous proteins and is found in both patients and animals post-consumption of alcohol. These TFA and MAA-adducts have been shown to cause the release of proinflammatory cytokines by endogenous inflammatory cells. If both adducts share a similar mechanism of cell activation, receiving general anesthesia following alcohol ingestion could exacerbate the inflammatory response caused by the inhaled general anesthetic halothane and lead to solid organ (including liver and brain) injury. Methods: Control diet and alcohol-fed rats were randomized to receive halothane pretreatments by intraperitoneal injection mixed in sesame oil. Following the intraperitoneal injections, the intact heart was removed, HECs were isolated and stimulated with unmodified bovine serum albumin (Alb), MAA-modified Alb (MAA-Alb), Hexyl-MAA, or lipopolysaccharide (LPS), and supernatant concentrations of TNF-α were determined. Results: Halothane pre-treated rat HECs demonstrated significantly greater TNF-α concentration following MAA-adduct and LPS stimulation than the non-halothane pre-treated in both pair and alcohol-fed rats, but was significantly greater in the alcohol-fed groups. Conclusion: These results demonstrate that halothane and MAA-adduct pre-treatment will increase the inflammatory response (TNF-α release) in rat HECs following LPS and MAA stimulation in vitro. Also, these results suggest that halothane exposure may increase the risk of alcohol-induced solid organ injury secondary to TNF-induced inflammation. Other investigators have reported similar proinflammatory cytokine release with other (isoflurane and sevoflurane) inhaled anesthetic exposure, suggesting inhaled anesthetics should be used with caution in alcohol consuming humans.

A Mechanism for Inhaled Anesthetic-Induced Solid Organ Injury: Inflammation

Background: Inhaled anesthetics, including halothane, iso- and sevoflurane induce proinflammatory cytokine release. Halothane is an inhaled anesthetic agent that is metabolized by the liver into a highly reactive product, trifluoroacetyl chloride, which can react endogenously to form a trifluoroacetyl-adduct (TFA-adduct). The MAA-adduct is formed by acetaldehyde and malondialdehyde reacting with endogenousproteins and is found in both patients and animals post-consumption of alcohol. These TFA and MAA-adducts have been shown to cause the release of proinflammatorycytokines by endogenous inflammatory cells. If both adducts share a similar mechanism of cell activation, receiving general anesthesia following alcohol ingestion could exacerbate the inflammatory response caused by the inhaled general anesthetic halothane and lead to solid organ (including liver and brain) injury. Methods: Control diet and alcohol-fed rats were randomized to receive halothane pretreatments by intraperitoneal injection mixed in sesame oil. Following the intraperitoneal injections, the intact heart was removed, HECs were isolated and stimulated with unmodified bovine serum albumin (Alb), MAA-modified Alb (MAA-Alb), Hexyl-MAA, or lipopolysaccharide (LPS), and supernatant concentrations of TNF-α were determined. Results: Halothane pre-treated rat HECs demonstrated significantly greater TNF-α concentration following MAA-adduct and LPS stimulation than the non-halothane pre-treated in both pair and alcohol-fed rats, but was significantly greater in the alcohol-fed groups. Conclusion: These results demonstrate that halothane and MAA-adduct pre-treatment will increase the inflammatory response (TNF-α release) in rat HECs following LPS and MAA stimulation in vitro. Also, these results suggest that halothane exposure may increase the risk of alcohol-induced solid organ injury secondary to TNF-induced inflammation. Other investigators have reported similar proinflammatory cytokine release with other (isoflurane and sevoflurane) inhaled anesthetic exposure, suggesting that inhaled anesthetics should be used with caution in alcohol consuming humans.

ANTIOXIDANT EFFECT OF PINEAPPLE (ANANAS COSMOSUS) PEEL EXTRACT ON ALCOHOL-INDUCED OXIDATIVE STRESS IN SPLENIC TISSUES OF MALE ALBINO RATS

ABSTRACT Oxidative stress was induced by oral administration of ethanol (20% w/v) at a dosage of 5 mL/kg body weight in rats. After 28 days of treatment, the rats were fasted overnight and sacrificed by cervical dislocation. Splenic tissue homogenates were used for the assessment of protein concentration, reduced glutathione (GSH), catalase, superoxide dismutase (SOD) and lipid peroxidation. Feeding on alcohol caused a significant decrease in GSH level in the group fed alcohol only, while treatment with pineapple peel extracts increased the GSH activities. No significant difference was observed in SOD levels of the negative control and group fed on only pineapple peel extract. There was an elevated catalase activity in the negative control. Pineapple peel extract significantly reduced it. Treatment with pineapple peel extracts was observed to reduce malondialdehyde (MDA) in alcohol-fed groups. Protein concentration increased after treatment with the extracts. This study indicates the protective effect of pineapple peel extract against alcohol-induced oxidative stress. PRACTICAL APPLICATIONS Pineapples are readily available in the tropics and subtropics almost all seasons. It can be grown in marginal conditions, with a minimum input cost. Fruits are used for human consumption as well as raw materials for most juice industries. However, its peels are not being utilized, thereby leading to a waste management problem. Utilization of the peels for medicinal purposes will therefore reduce the cost of waste management and also be of tremendous benefit to the medical world in the management of various ailments.

Beneficial Role of Dietary Folic Acid on Cholesterol and Bile Acid Metabolism in Ethanol-Fed Rats

Cholesterol metabolism is altered by chronic ethanol consumption. In previous articles, we demonstrated the anti-oxidant capacity of folic acid, which may be useful in the prevention of damage provoked by ethanol. We want to determine the effects of ethanol on cholesterol and bile metabolism and whether a folic acid-supplemented diet could change alterations provoked by a chronic ethanol intake in rats. We used four experimental groups: (1) control, (2) alcohol, (3) alcohol supplemented with folic acid, and (4) control supplemented with folic acid. In all the experimental groups, we measured hepatic 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, and cholesterol and bile acids in serum, liver, bile, and feces. We have found that the alcohol-fed groups showed high hepatic HMG-CoA reductase activity, total hepatic and serum cholesterol concentration, bile cholesterol secretion concentration, and cholesterol enterohepatic circulation. Total serum and hepatic cholesterol levels decreased when alcohol-fed rats were supplemented with folic acid. The hepatic bile acid concentration increased in both chronic ethanol groups. Folic acid supplementation significantly increased bile cholesterol secretion, the bile acids in bile, and fecal bile acid excretion in ethanol-exposed rats. The independent bile acid fraction showed no significant differences between both ethanol groups with respect to Na+, K+, and Cl- concentrations. Folic acid increases bile flow, bile acid synthesis from cholesterol, and bile acid excretion via feces, thus provoking a decrease in serum and hepatic cholesterol. However none of these actions were observed in supplemented control rats. This, therefore, could be yet another beneficial effect of folic acid on alcoholic patients.

The effects of chronic alcohol consumption and exercise on the skeleton of adult male rats.

Lifestyle factors are known to affect skeletal development and integrity. Specifically, running has been reported to increase risk of fatigue fractures, whereas chronic alcohol consumption has been shown to reduce bone formation and bone mass. The combined effect of exercise and alcohol on the skeleton has yet to be explored, although alcohol consumption is common among certain physically active populations (e.g., military recruits, college athletes). It was hypothesized that chronic alcohol consumption would accentuate the inherent risk associated with endurance running exercise. Six-month-old male Sprague Dawley rats were assigned to one of five groups: baseline, exercise-alcohol diet, exercise-normal diet, sham-alcohol diet, and sham-normal diet. Alcohol-fed rats (35% caloric intake) received a liquid diet ad libitum. Normal animals were pair-fed the identical diet with a maltose dextrin caloric substitute. Exercise was conducted on a motorized treadmill 5 days/wk for 16 weeks. Sham rats were placed on a stationary treadmill for matching time periods. Fluorochrome labels were administered 3 days before baseline and at 10 and 2 days before animals were killed. Heart, soleus, and rectus femoris muscles were wet weighed to assess the effects of training. Tibiae were collected for static and dynamic histomorphometric measurements on cancellous and cortical bone. Muscle weights were larger in the exercised rats versus the sham rats. Alcohol had no significant effect on skeletal muscle weight but did result in larger heart weights in both alcohol-treated groups. Cancellous and periosteal bone formation rates were significantly decreased in the alcohol-fed rats versus rats on the normal diet and were associated with a significant reduction in trabecular thickness in the tibial metaphysis. Cortical and cross-sectional areas were also significantly lower in the alcohol-fed groups compared with the non-alcohol-fed groups. Exercise had no significant effect on cancellous or cortical bone measurements. Chronic alcohol consumption significantly reduced bone formation. Exercise had no effect on the bone and did not attenuate any of the negative effects of alcohol. The results suggest that alcohol consumption weakens the skeleton and increases the incidence of endurance-exercise-related bone injuries. Thus, individuals who are participating in endurance exercise and consuming alcohol may be at greater risk for exercise-related skeletal injuries. Further investigation of the potential for alcohol to induce detrimental effects on the hearts of individuals participating in endurance exercise is indicated.

The effects of chronic alcohol consumption and exercise on the skeleton of adult male rats

Background Lifestyle factors are known to affect skeletal development and integrity. Specifically, running has been reported to increase risk of fatigue fractures, whereas chronic alcohol consumption has been shown to reduce bone formation and bone mass. The combined effect of exercise and alcohol on the skeleton has yet to be explored, although alcohol consumption is common among certain physically active populations (e.g., military recruits, college athletes). It was hypothesized that chronic alcohol consumption would accentuate the inherent risk associated with endurance running exercise. Methods Six-month-old male Sprague Dawley® rats were assigned to one of five groups: baseline, exercise-alcohol diet, exercise-normal diet, sham-alcohol diet, and sham-normal diet. Alcohol-fed rats (35% caloric intake) received a liquid diet ad libitum. Normal animals were pair-fed the identical diet with a maltose dextrin caloric substitute. Exercise was conducted on a motorized treadmill 5 days/wk for 16 weeks. Sham rats were placed on a stationary treadmill for matching time periods. Fluorochrome labels were administered 3 days before baseline and at 10 and 2 days before animals were killed. Heart, soleus, and rectus femoris muscles were wet weighed to assess the effects of training. Tibiae were collected for static and dynamic histomorphometric measurements on cancellous and cortical bone. Results Muscle weights were larger in the exercised rats versus the sham rats. Alcohol had no significant effect on skeletal muscle weight but did result in larger heart weights in both alcohol-treated groups. Cancellous and periosteal bone formation rates were significantly decreased in the alcohol-fed rats versus rats on the normal diet and were associated with a significant reduction in trabecular thickness in the tibial metaphysis. Cortical and cross-sectional areas were also significantly lower in the alcohol-fed groups compared with the non-alcohol-fed groups. Exercise had no significant effect on cancellous or cortical bone measurements. Conclusions Chronic alcohol consumption significantly reduced bone formation. Exercise had no effect on the bone and did not attenuate any of the negative effects of alcohol. The results suggest that alcohol consumption weakens the skeleton and increases the incidence of endurance-exercise-related bone injuries. Thus, individuals who are participating in endurance exercise and consuming alcohol may be at greater risk for exercise-related skeletal injuries. Further investigation of the potential for alcohol to induce detrimental effects on the hearts of individuals participating in endurance exercise is indicated.

Alcohol Consumption Inhibits Osteoblastic Cell Proliferation and Activity In Vivo

To better understand the effect of alcohol consumption on the bone remodeling process in vivo, we used a rodent animal model system to compare osteoblast activity and number in alcohol-fed, pair-fed, and chow-fed animals. Adult, virgin female Sprague–Dawley rats were assigned to alcohol-fed, pair-fed, and chow groups based on weights. Alcohol animals were fed a liquid diet containing 35% ethanol-derived calories for 6 weeks. Pair-fed animals were matched to test animals on the basis of initial weight and fed an isocaloric diet equivalent to that consumed by the alcohol-matched animals on the previous day with alcohol replaced by maltose-dextrin. Right tibias were fixed and embedded in methyl methacrylate for sectioning. Sections (5 μm) were stained for cement lines and packets were measured using histomorphometric techniques on a BioQuant morphometric system. Alcohol-fed animals exhibited statistically significant decreases in the amount of bone surface containing active osteoblasts and a decrease in mean wall thickness. Osteocalcin values were significantly reduced from pair-fed levels and slightly, but not significantly, reduced from chow-fed animals.

Intracerebral grafts promote recovery of the cholinergic innervation of the hippocampal formation in rats withdrawn from chronic alcohol intake. An immunocytochemical study

We have previously found that alcohol withdrawal aggravates the neuronal cell loss induced by chronic alcohol consumption in the rat hippocampal formation. We have also shown that intracerebral grafts of immature hippocampal tissue could reverse the progressive degeneration that occurs during this withdrawal. Furthermore, we have shown that chronic alcohol consumption reduces the areal density of choline acetyltransferase-immunoreactive neurons and the density of choline acetyltransferase-immunoreactive fibres in the hippocampal formation. Thus, we thought it would be of interest to investigate the effects of alcohol withdrawal in the hippocampal cholinergic innervation and to determine whether the intracerebral grafting of immature hippocampal tissue would have beneficial effects upon the cholinergic system in this condition. Choline acetyltransferase-immunoreactive fibres and perikarya were analysed in 14-month-old control, alcohol-fed, withdrawal and withdrawal-grafted groups of rats. The areal density of choline acetyltransferase-immunoreactive neurons was reduced in all experimental groups when compared to controls. The density of choline acetyltransferase-immunoreactive fibres was lower in the alcohol-fed and withdrawal groups than in the control and withdrawal-grafted groups. We conclude that the grafted tissue probably produced neurotrophic factors which allowed a recovery of the hippocampal cholinergic fibre network. This recovery might be of importance to reverse the cognitive dysfunction described after chronic alcohol consumption and withdrawal.

NMR investigation of the futile cycling of ethanol in chronic alcoholic rats.

Weight gain efficiency differences previously reported between alcohol-fed rats and their controls were investigated. Additionally, the futile cycling of ethanol proposed to explain such differences was studied by NMR spectroscopy. Male Sprague-Dawley rats were fed a nutritionally adequate diet containing 36% of the calories as alcohol, and their paired controls were fed an isocaloric diet for 11 weeks to establish conditions of chronic alcohol feeding. Normalized metabolic efficiencies varied significantly during the initial 2-week period (6.86 +/- 0.51 vs. 2.83 +/- 0.18 g/kcal x 10(-2) for control and alcohol-fed groups, respectively, and to a lesser extent over the entire feeding period (6.41 +/- 0.78 vs. 4.60 +/- 0.27 g/kcal x 10(-2) for control and alcohol-fed groups, respectively. Alcohol-induced weight gain inefficiency in metabolism has previously been studied and explained by a variety of different biochemical and physiological mechanisms. One possible pathway of energy wastage may occur due to ethanol futile cycling from ethanol to acetaldehyde through the microsomal ethanol oxidation system pathway, and simultaneously from acetaldehyde to ethanol via the ADH pathway. This futile cycle represents a net loss of 6 ATP/cycle, corresponding to the loss of two reducing equivalents (NADH and NADPH). 1H NMR spectroscopy was used to test for this cycling in blood extracts after administration of 1,1-2H2 ethanol. No futile cycling was detected either during the initial 2 weeks of feeding or after the entire feeding period.

Effect of exposure to an alcohol diet for 10 days on the ability of interleukin-1 beta to release ACTH and corticosterone in the adult ovariectomized female rat.

Adult ovariectomized female rats were fed an alcohol diet for 10 days. Animals fed ad libitum, or fed an isocaloric diet (pair-fed), were also included in all experiments. The intravenous injection of interleukin-1 beta caused dose-related increases in plasma adrenocorticotropic hormone (ACTH) levels in all three groups of rats. However, alcohol-fed animals showed a significant blunting of their ACTH, but not corticosterone response, in comparison with rats fed ad libitum or pair-fed. In contrast, corticotropin-releasing factor (CRF) injection caused overall statistically comparable ACTH secretory rates in all animals, although small differences were observed in some cases. Exposure to mild electroshocks for 30 min significantly increased ACTH values in all animals, but alcohol-fed rats again showed blunted release. In this paradigm, pair-fed animals exhibited a response that was intermediate between that of the ad libitum and alcohol-fed groups. We conclude that chronic alcohol consumption decreases the response of the hypothalamic-pituitary axis to cytokines and mild footshocks. This suggests that the activity of both CRF nerve terminals in the median eminence, and of CRF perikarya in the hypothalamus, is inhibited by this treatment, although pituitary responsiveness to CRF appears unchanged.

Effects of chronic alcohol consumption and withdrawal on the somatostatin-immunoreactive neurons of the rat hippocampal dentate hilus.

Previous studies have demonstrated that the dentate granule and the CA3 pyramidal cells of the rat hippocampal formation are neuronal populations vulnerable to the toxic effects of ethanol. It also has been shown that the resulting alterations do not end after withdrawal from ethanol. As the neurons in the dentate hilus are heavily interconnected with the dentate granule cells, the authors decided to examine the fate of the hilar neurons after chronic alcohol consumption and withdrawal, inasmuch as the hilar somatostatin-immunoreactive (SS-I) neurons were found to be sensitive to cerebral ischemia and to seizures. The following groups of adult rats were studied: (1) alcohol-fed for 6 and 12 months; (2) alcohol-fed for 6 months and then switched to water for a further 6 months; (3) pair-fed controls; and (4) controls fed ad libitum. The authors determined the numerical density of hilar neurons and the number of its SS-I subpopulation. These were found to be significantly reduced in both the alcohol-fed and withdrawal groups when compared with the respective age-matched controls. The consequent loss of the integrative action of the hilar neurons, including the SS-Is, could explain some of the alcohol-related functional deficits as well as their persistence after withdrawal.

Microsomal Δ9, Δ6 and Δ5 desaturase activities and liver membrane fatty acid profiles in alcohol‐fed rats

In experimentally produced alcoholic fatty liver microsomal fatty acid composition was measured using gas chromatography. The results showed an increase in linoleic acid (18:2, n-6) and hexadecaenoic acid (22:6, n-3) and a decrease in arachidonic acid (20:4, n-6) in alcohol-fed rats. Using high performance liquid chromatographic separation of radiolabelled substrate and products, delta 9, delta 6 and delta 5 desaturase enzymes were assayed. The activity of delta 9 and delta 5 desaturase was decreased in alcohol-fed rats and delta 6 desaturase activity was similar in control and alcohol-fed groups. These results indicated there was no causal relationship between desaturase activity and membrane fatty acid changes. Increased amounts of eicosatrienoic acid (20:3, n-9) in rats fed less than 5% fat were observed in both control and alcohol-fed rats. The results indicated that essential fatty acid deficiency was not due to alcohol consumption.

Effects of chronic alcohol intake and withdrawal on the prefrontal neurons and synapses

Previous studies demonstrated that alcohol induces marked deterioration of the cerebral cortex. However, quantitative evaluations of neurons and synapses of the prefrontal cortex from chronic alcohol-fed and withdrawn animals are nonexistent, in spite of the functional implications that can underlie structural changes in this cortical area. To achieve this evaluation, we used groups of rats alcohol-fed for 6, 12 and 18 months, their respective controls as well as groups of rats alcohol-fed for 6 and 12 months and then switched to water for 6 months—withdrawal groups. The thickness of the prelimbic cortical layers I–III was reduced in the alcohol-fed and withdrawal groups. A significant reduction in the density of cells was found, which was more marked after withdrawal. Conversely, the density of synapses increased after alcohol exposure and withdrawal; such numerical shifts lead to a significant increase in the synapse-to-neuron ratio. These results indicate that the cortical circuitry of the prelimbic cortex is vulnerable to prolonged periods of alcohol exposure and withdrawal and allow to advance the view that the alterations can induce functional implications.

Metric analysis of hippocampal granule cell dendritic trees after alcohol withdrawal in rats.

It was previously demonstrated that after prolonged alcohol consumption, dendrites might display either degenerative or plastic changes according to the central nervous system areas studied. Furthermore, and rather unexpectedly, we also found that withdrawal from alcohol led to a decrease of the relative number of granule cells in the fascia dentata. Thus, it seemed worthwhile to quantify, using a semiautomatic measuring system, the dendritic arborizations of hippocampal granule cells of rats alcohol-fed for 12 months followed by 6 months of abstinence and compare the results with age-matched control and alcohol-fed groups. The results indicate smaller dendritic trees in the abstinent group when compared with the higher values of the dendritic parameters found in alcohol-fed rats.

Remodeling of the cerebellar glomeruli after long-term alcohol consumption in the adult rat

The morphological effects of the prolonged alcohol consumption on the cerebellar glomeruli of adult rats were studied in groups of controls and animals fed alcohol for 1, 3, 6, 12 and 18 months, by applying qualitative and quantitative ultrastructural methods. Following 6 months of alcohol consumption degenerated granule cell dendritic profiles were randomly dispersed over the granular layer surrounding mossy fiber terminals. In 12- and 18-month alcohol-fed groups, some glomeruli appeared with an atrophic design owing to the lack of their post-synaptic targets while others presented a remodeled organization, with Golgi cell dendrites replacing the missing granule cell digits. An extensive glial reaction was seen investing both types of glomeruli. The total number of synapses per glomerulus remained unchanged in all groups. this is due to an increase of the mossy fiber terminal—Golgi cell dendrite synapses, which compensate the decrease of the mossy fiber terminal — granule cell dendrite synapses. It is suggested that the morphological remodeling of the cerebellar glomeruli after long-term alcohol consumption can lead to changes in the balance of the excitatory-inhibitory activities of the cerebellar circuitry. This could be related to the important functional changes observed in the cerebellum under these circumstances.

Lipofuscin granules in Purkinje cells after long-term alcohol consumption in rats.

The increased number of lipofuscin granules in Purkinje cells from chronic alcohol-fed rats was studied by morphometric methods. These granules were autofluorescent and had marked acid phosphatase activity. No significant changes were found in the mean nuclear and perikaryon volumes when alcohol-fed and control groups were compared. The number of lipofuscin granules per unit of surface area of cell cytoplasm (Na) and their volumetric density (Vv) were significantly greater in alcohol-fed groups than in controls. These values were also significantly different when the 6- and 12-month control groups were compared. Na and Vv values in alcohol-fed groups increased progressively. The increased number is probably related to disturbances in neuronal cell metabolism. The importance of age and malnutrition in the formation of these granules was also considered.

Alcohol-induced granule cell loss in the cerebellar cortex of the adult rat

The effect of chronic alcohol treatment on granule cells from the adult rat cerebellar cortex was examined. Groups of controls and animals fed alcohol for 1, 3, 6, 12, and 18 months were studied using light morphometric and ultrastructural methods. Dark degeneration of granule-cell soma and their neurites was noted after 3 months of the alcohol treatment. In the 1- and 3-month alcohol-fed groups, the numerical density of granule cells (N v), as well as the fraction of the layer occupied by them (V vgr), showed no significant differences compared with controls. These same parameters were significantly reduced in the 6-, 12-, and 18-month alcohol-fed groups compared with controls. No significant changes were found within controls. There was a progressive and significant decrease in N v and V vgr in the alcohol-fed groups. All results were independent of changes in the mean width of the granular layer. These data support the conclusion that long-term alcohol consumption in adult animals induces neuronal loss in the nervous system.