Moderate Ethanol Research Articles

Moderate prenatal ethanol exposure in the rat promotes kidney cell apoptosis, nephron deficits, and sex-specific kidney dysfunction in adult offspring.

Alcohol during pregnancy can impair fetal development and result in offspring with neurodevelopmental deficits. Less is known about how low to moderate alcohol exposure can affect other organs, such as the kidney. Here, the effects of moderate ethanol exposure throughout pregnancy on kidney development were examined using a rat model. Rats were fed a liquid diet containing 6% ethanol (vol/vol) or control (0% ethanol) throughout pregnancy. Kidneys were collected at embryonic day (E) 20 or postnatal day (PN) 30 and total glomerular (nephron) number determined using unbiased stereology. Kidney function was examined in offspring at 8 and 19 months. At E20, fetuses exposed to ethanol had fewer nephrons with increased apoptosis. Alcohol exposure caused kidney dysregulation of pro- (Bax) and anti- (Bcl-2) apoptotic factors, and reduced expression of the cell proliferation marker, Ki67. Prenatal alcohol decreased expression of Gdnf and Tgfb1, important regulators of branching morphogenesis, in male fetuses. At PN30, kidney volume and nephron number were lower in offspring exposed to prenatal alcohol. Urine flow and osmolality were normal in offspring exposed to alcohol however sodium excretion tended to be lower in females prenatally exposed to alcohol. Findings suggest exposure to moderate levels of alcohol during pregnancy results in impaired kidney development and leads to a permanent nephron deficit. Although the impact on adult kidney function was relatively minor, these data highlight that even at moderate levels, alcohol consumption during pregnancy can have deleterious long-term outcomes and should be avoided.

Magnetic Resonance Imaging and Micro-Computed Tomography reveal brain morphological abnormalities in a mouse model of early moderate prenatal ethanol exposure

BackgroundThis study investigated the effects of early moderate prenatal ethanol exposure (PEE) on the brain in a mouse model that mimics a scenario in humans, whereby moderate daily drinking ceases after a woman becomes aware of her pregnancy. MethodsC57BL/6J pregnant mice were given 10% v/v ethanol from gestational day 0–8 in the drinking water. The male offspring were used for imaging. Anatomical and diffusion Magnetic Resonance Imaging were performed in vivo at postnatal day 28 (P28, adolescence) and P80 (adulthood). Micro-Computed Tomography was performed on fixed whole heads at P80. Tensor-based morphometry (TBM) was applied to detect alterations in brain structure and voxel-based morphometry (VBM) for skull morphology. Diffusion tensor and neurite orientation dispersion and density imaging models were used to detect microstructural changes. Neurofilament (NF) immunohistochemistry was used to validate findings by in vivo diffusion MRI. ResultsTBM showed that PEE mice exhibited a significantly smaller third ventricle at P28 (family-wise error rate (FWE), p < 0.05). All other macro-structural alterations did not survive FWE corrections but when displayed with an uncorrected p < 0.005 showed multiple regional volume reductions and expansions, more prominently in the right hemisphere. PEE-induced gross volume changes included a bigger thalamus, hypothalamus and ventricles at P28, and bigger total brain volumes at both P28 and P80 (2-sample t-tests). Disproportionately smaller olfactory bulbs following PEE were revealed at both time-points. No alterations in diffusion parameters were detected, but PEE animals exhibited reduced NF positive staining in the thalamus and striatum and greater bone density in various skull regions. ConclusionOur results show that early moderate PEE can cause alterations in the brain that are detectable during development and adulthood.

Improved measurement of ethyl glucuronide concentrations in hair using UPLCMS/MS for the evaluation of chronic ethanol consumption

The presence of Ethyl glucuronide (EtG) in hair provides a strong indication of ethanol consumption and its investigation is of interest in both clinical and forensic contexts because of the wide window of detection. However, due to the possibility of false negative results in cases of small ethanol intake or excessive hair washing, the combined measurement of ethyl palmitate (EtP) with EtG could be useful. In this study, a sensitive UHPLC-MS/MS procedure for the measurement of EtG in hair was developed and validated, using optimized sample preparation and chromatographic separation. Milled hair was extracted with water for 24 h at room temperature, followed by clean-up of the extract by ion-exchange solid phase extraction (SPE). Extraction was highly efficient, with yield of 96.93–101.06%. Chromatographic separation was performed with a Fluoro-Phenyl stationary phase. The assay was linear from 4 to 500pgmg−1, with accuracy in the range of 100.30–106.16%. Matrix effects (−0.87 to 5.89%) were adequately compensated by the use of deuterated EtG as internal standard. EtG was measured in hair samples of 46 volunteers, and results were compared with hair concentrations of ethyl palmitate (EtP) and the score in the AUDITC questionnaire. EtG hair concentrations were significantly correlated to the AUDIT-C classification (rs=0.365, p<0.05), but not to EtP hair levels. The diagnostic performance of EtG hair concentrations to identify excessive or moderate ethanol use was similar to the capability of AUDIT-C to identify severe and high health risk (Kappa, p=0.013). The developed assay is suitable for clinical use, providing a useful tool to evaluate chronic ethanol consumption.

Continuous UiO-66-Type Metal-Organic Framework Thin Film on Polymeric Support for Organic Solvent Nanofiltration.

For the first time, continuous polycrystalline UiO-66-NH2 thin film supported by a cross-linked Matrimid substrate was successfully fabricated via in situ solvothermal synthesis at room temperature for organic solvent nanofiltration. The integrated structure of the formed UiO-66-NH2 selective layer was inferred by various characterizations including X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. We have demonstrated that pretreatment of the substrate by an organic ligand, the number of solvothermal synthesis cycles, and the reaction time play important roles in MOF film formation. The newly developed UiO-66-NH2 membrane possesses high surface hydrophobicity and mean pore size of 0.89 nm in diameter. It shows an exceptional rejection of 96.33% to Rose Bengal with moderate ethanol permeance of 0.88 L m-2 h-1 bar-1. Benefiting from the extraordinary chemical stability of Zr-MOF crystals, the UiO-66-NH2 membrane shows excellent stability in different solvents, implying their great potential for real applications. This work provides useful insights into the fabrication of continuous UiO-66-type MOF membranes on polymeric substrates, which are very promising in practical separations involving organic solvents.

Moderate Alcohol Consumption Inhibits Sodium-Dependent Glutamine Co-Transport in Rat Intestinal Epithelial Cells in Vitro and Ex Vivo.

Malnutrition is present in chronic alcoholics. However, how moderate alcohol consumption affects the absorption of nutrients like glutamine has not been investigated. Glutamine, an amino acid, is vital to gastrointestinal health. Glutamine is absorbed via sodium-dependent glutamine co-transport (B0AT1; SLC6A19) along the brush border membrane of absorptive villus cells. Rat intestinal epithelial cells (IEC-18) and sixteen-week-old Sprague Dawley rats were administered the equivalent of a 0.04% blood alcohol content of ethanol (8.64 mM; 2 g/kg) to investigate the effect of moderate alcohol on sodium-glutamine co-transport. Sodium-dependent 3H-glutamine uptakes were performed to measure B0AT1 activity. Inorganic phosphate was measured as a function of Na-K-ATPase activity. Protein expression was analyzed by immunohistochemical and Western blot analysis. Ethanol significantly inhibited sodium-dependent glutamine absorption and Na-K-ATPase activity in enterocytes in vitro and ex vivo. Kinetic studies suggested that the mechanism of inhibition was due to decreased maximal rate of uptake (Vmax) of the B0AT1 co-transporter, corresponding to decreased B0AT1 protein expression and secondary to an inhibited sodium-gradient at the cellular level in vitro and ex vivo. In all, moderate ethanol significantly inhibited glutamine absorption at the level of decreased B0AT1 expression at the brush border membrane and a reduced sodium gradient, which may contribute to malnutrition present in chronic alcoholics.

Caffeine modulates voluntary alcohol intake in mice depending on the access conditions: Involvement of adenosine receptors and the role of individual differences

Caffeine is the most consumed psychoactive stimulant and the main active ingredient of energy drinks. Epidemiology studies have shown a positive correlation between the consumption of energy drinks and that of ethanol. The popular belief is that caffeine antagonizes the intoxicating effects of alcohol. Both drugs act on the adenosine system but have opposite effects. Caffeine is a methylxanthine that acts as a nonselective adenosine receptor antagonist, binding to A1 and A2A receptor subtypes. In contrast, ethanol increases extracellular adenosinergic tone. The purpose of this study was to examine the impact of a broad range of doses of caffeine and of selective adenosine A1 and A2A receptor antagonists on voluntary ethanol intake under different ethanol access conditions. C57BL/6 J male mice had access to ethanol (10% w/v) under different conditions: restricted (2 h in the dark), unrestricted (24 h access), or after 4 days of alcohol removal following several periods of unrestricted access. Mice reduced ethanol intake in the restricted access condition after receiving caffeine (20.0 mg/kg), or theophylline (20.0 mg/kg), another methylxanthine. Selective A1 and A2A adenosine receptor antagonists, or their combination, did not have any effect. However, under unrestricted access conditions caffeine and the adenosine A2A receptor antagonist increased ethanol intake. After splitting animals into high, moderate and low ethanol consumers, caffeine (2.5–20.0 mg/kg) significantly increased ethanol consumption in moderate consumers with no effect on low or high consumers. In addition, after reintroducing ethanol access, caffeine (5.0 mg/kg) decreased ethanol consumption among moderate consumers. Thus, caffeine produced different effects on ethanol intake depending on the access condition and the baseline consumption of ethanol.

BK channel clustering is required for normal behavioral alcohol sensitivity in C. elegans

The large conductance, calcium- and voltage-activated potassium channel, known as the BK channel, is one of the central proteins that mediate alcohol intoxication and tolerance across species. Although ethanol targets BK channels through direct interaction, how ethanol-mediated BK channel activation causes behavioral intoxication is poorly understood. In. C. elegans, loss of function in SLO-1, the BK channel ortholog, confers profound ethanol resistance in movement and egg-laying behaviors. Here, we show that depletion of SLO-1 channels clustered at the active zones with no change in the overall channel expression level results in locomotory resistance to the intoxicating effect of ethanol, equivalent to that of slo-1 loss-of-function mutants. Likewise, depletion of clustered SLO-1 channels in the sarcolemma and neurons leads to ethanol-resistant egg-laying behavior. By contrast, reduction in the overall SLO-1 channel level by over 70% causes only moderate ethanol resistance in movement, and minimal, if any, resistance in egg laying. Our findings strongly suggest that behavioral ethanol sensitivity is conferred by local, but not global, depression of excitability via clustered BK channels. Given that clustered BK channels are functionally coupled to, and localize near, calcium channels, ethanol may mediate its behavioral effects by targeting BK channels and their coupled calcium channels.

Moderate chronic ethanol consumption exerts beneficial effects on nonalcoholic fatty liver in mice fed a high-fat diet: possible role of higher formation of triglycerides enriched in monounsaturated fatty acids.

Several clinical studies suggested that light-to-moderate alcohol intake could alleviate nonalcoholic fatty liver disease (NAFLD), but the underlying mechanism is still poorly understood. Mice fed a high-fat diet (HFD) were submitted or not to moderate ethanol intake for 3months (ca. 10g/kg/day) via drinking water. Biochemical, analytical and transcriptomic analyses were performed in serum and liver. Serum ethanol concentrations in ethanol-treated HFD mice comprised between 0.5 and 0.7g/l throughout the experiment. NAFLD improvement was observed in ethanol-treated HFD mice as assessed by reduced serum transaminase activity. This was associated with less microvesicular and more macrovacuolar steatosis, the absence of apoptotic hepatocytes and a trend towards less fibrosis. Liver lipid analysis showed increased amounts of fatty acids incorporated in triglycerides and phospholipids, reduced proportion of palmitic acid in total lipids and higher desaturation index, thus suggesting enhanced stearoyl-coenzyme A desaturase activity. mRNA expression of several glycolytic and lipogenic enzymes was upregulated. Genome-wide expression profiling and gene set enrichment analysis revealed an overall downregulation of the expression of genes involved in collagen fibril organization and leukocyte chemotaxis and an overall upregulation of the expression of genes involved in oxidative phosphorylation and mitochondrial respiratory chain complex assembly. In addition, mRNA expression of several proteasome subunits was upregulated in ethanol-treated HFD mice. Moderate chronic ethanol consumption may alleviate NAFLD by several mechanisms including the generation of non-toxic lipid species, reduced expression of profibrotic and proinflammatory genes, restoration of mitochondrial function and possible stimulation of proteasome activity.

Maternal manipulation during late gestation (GDs 17-20) enhances ethanol consumption and promotes changes and opioid mRNA expression in infant rats

Fetal ethanol experience generates learning and memories capable to increase ethanol consummatory behaviors during infancy. Opioid system seems to be involved in mediating those alcohol-related behaviors. In this work, we proposed to study the impact of prenatal exposure to a moderate ethanol dose, upon ingestion of the drug and possible ethanol-induced molecular changes on opioid precursor peptides (POMC, Pro-enk and Pro-DYN) and receptors (MOR, DOR and KOR) mRNA expression, in hypothalamus. Pregnant rats received during gestational days (GDs) 17-20, a daily intragastric (i.g.) administration with 2g/kg ethanol or water. A third group of dams was left undisturbed during pregnancy (Unmanipulated group). Intake test was conducted at postnatal days (PDs) 14-15. Three groups of pups were performed: control (no intake test), water (vehicle) and 5% ethanol. At the end of intake test blood samples were taken to quantify blood ethanol concentrations (BECs) and hypothalamus sections were obtained to perform qRT-PRC assessment of opioid precursor peptides and receptors. The analysis of the consummatory responses (% of consumption) and pharmacokinetic profiles (BECs) suggested that maternal manipulation induced by i.g. intubations, during the last four days of gestation (whenever ethanol or water), are sufficient to induce infantile ethanol intake during infancy. Gene expression from the hypothalamus of unmanipulated group revealed that infantile ingestive experiences with ethanol can down-regulate expression of mRNA Pro-Dyn and up-regulate mRNA expression of MOR and KOR. Finally, MOR mRNA expression was attenuated by prenatal i.g. manipulation in pups exposed to 5% ethanol.

Effects of puerarin on spatial learning and memory function in mice with acute alcohol consumption: An evaluation based upon firing rate and oxygen saturation analysis.

Ethanol is associated with various medical comorbidities affecting the brain and central nervous system. The use of puerarin in treating alcohol-induced memory disorders is systematically evaluated in this study based upon an analysis of the firing rate and oxygen saturation (SO2). A multi-channel data acquisition system and near-infrared spectroscopy (NIRS) were combined to obtain the electroneurophysiological signals and SO2 in the hippocampus of mice from the Institute of Cancer Research (ICR) after ethanol injection. A T-maze test was performed to study the alteration of spatial memory function. Ethanol was administered intraperitoneally (i.p.) in 2 dosages (1.5 g/kg and 0.5 g/kg). To investigate the effects of puerarin against acute ethanol-induced memory impairment, the same parameters corresponding to electroneurophysiological signals, SO2 and behavior performance in mice were also recorded upon the supplementation of puerarin in 2 dosages (25 mg/kg and 50 mg/kg). An inhibited firing rate and decreased SO2 were found in mice treated with an ethanol dose of 1.5 g/kg, which resulted in a low correct choice rate in the T-maze test, while an opposite trend appeared in mice which had been administered a moderate ethanol dose (0.5 g/kg). The trend of SO2 was positively correlated with that of the firing rate. A decreased firing rate and SO2 were accompanied by a decrease in the correct choice rate. With the supplementation of puerarin, a significant increase in the mean firing rate and SO2, as well as an improved correct choice rate, can be found in mice injected with excessive ethanol. The electroneurophysiological signals and NIRS were combined for the first time to prove that an excessive intake of ethanol can inhibit the spatial learning and memory function of mice. The supplementation of puerarin can suppress these adverse effects induced by ethanol at a high dosage, as evidenced by the increased firing rate and SO2.

Prenatal ethanol exposure and enkephalinergic neurotransmission.

Endogenous opioids (enkephalins, endorphins and dynorphins) are small peptides that play a main role in pain perception and analgesia, as well as in alcohol (ethanol) reinforcement and reward. Alcohol reinforcement involves the ethanol-induced activation of the endogenous opioid system, a process that may augment the hedonic value and the reinforcing properties of the drug, which in turn increases substance consumption. Changes in opioidergic transmission may contribute to alcohol intoxication and to the neuroadaptive responses produced by the long-lasting exposure to ethanol. Opioidergic transmission may be altered by ethanol at distinct levels, including the expression of precursor mRNAs, biosynthesis and release of opioid peptides, as well as ligand binding to opioid receptors. In adult rats, β-endorphinergic and enkephalinergic transmission, through activation of mu and delta opioid receptors, mediate ethanol reinforcement and high alcohol drinking behavior. Prenatal ethanol exposure (PEE) selectively modifies Methionine-enkephalin (Met-enk) content in several brain regions of infant and adolescent rats, particularly those of the reward circuits. In preweanling rats, Met-enk content is decreased in the ventral tegmental area but is increased in the prefrontal cortex and the nucleus accumbens and other brain areas, as a consequence of a short and moderate ethanol exposure during late gestation. PEE also increases Met-enk levels in the prefrontal cortex and other brain regions of 30-day-old adolescent rats. These findings suggest that mesocorticolimbic enkephalins are essential in ethanol reinforcement in offspring, as previously reported in adult rats.

Prenatal ethanol exposure attenuates sensitivity to the aversive effects of ethanol in adolescence and increases adult preference for a 5% ethanol solution in males, but not females.

The present set of experiments investigated the effects of a moderate dose of ethanol (2g/kg; 20% v/v intragastrically) during late gestation (G17-20 [gestational day]) on ethanol-induced conditioned taste aversion (CTA) in adolescence, and on ethanol consumption during adolescence and early adulthood. In experiment 1, male and female Sprague-Dawley rats were given 30-min access to a sweetened "supersaccharin" (SS) solution or sodium chloride (NaCl), followed by an intraperitoneal injection of 20% ethanol (0, 1, 1.25, or 1.5g/kg) for three conditioning/test sessions. Among animals conditioned with SS, prenatally ethanol-exposed males exhibited attenuated ethanol-induced CTA relative to males prenatally gavaged with water or non-manipulated, whereas prenatal treatment had no effect on CTA in females. Among animals conditioned with NaCl, there were no exposure group differences in males, with modest evidence for attenuated CTA in prenatally ethanol-exposed females. In experiment 2, the effects of prenatal ethanol exposure on ethanol consumption in adolescents (P35±1 day [postnatal day]) and adults (P56-60) were explored. At the beginning of the dark cycle, pair-housed rats were given three bottles containing 0, 5, and 10% ethanol for 18h every other day (i.e., Monday, Wednesday, Friday) for 3 weeks. Relative to water controls, adult males prenatally exposed to ethanol showed greater preference and more intake (g/kg) of 5% ethanol, while showing lower intake of 10% ethanol. These intake and preference differences were not evident in adolescent males. Among females at both ages, ethanol-exposed animals showed lower preference and intake (g/kg) of 5% ethanol than their water-exposed controls. Thus, moderate ethanol exposure during late gestation produced a largely male-specific attenuation in the aversive effects of ethanol during adolescence that could contribute to later increases in preference and intake of a 5% ethanol solution, although this emergent effect was not evident in adolescence (or in females), but only manifested in adulthood.

Effects of Moderate Ethanol Consumption on Lipid Metabolism and Inflammation Through Regulation of Gene Expression in Rats.

Epidemiological studies and experimental data from rodent models have reported a non-linear relationship between consumption of alcohol and cardiovascular disease (CVD) risk that suggests that light-to-moderate drinking as opposed to excessive consumption may provide some cardiovascular benefits. The present study examined potential mechanisms by which moderate alcohol consumption may provide a protective effect against CVD. Wistar rats exposed for 3 months to a 20% ethanol intermittent-access voluntary drinking paradigm displayed a reduction in epididymal fat, blood glucose and non-HDL and total cholesterol. These effects were accompanied by decreased expression of Hmgcr, Srebp-2, Cox-2 and RelA, indicating downregulation of genes involved in cholesterol synthesis and inflammation. Twenty-four male Wistar rats voluntarily consumed a 20% v/v ethanol solution on alternate days for 13 weeks (ethanol-treated) or were given access to water alone (non-ethanol-exposed control). There was no difference in body weight gain between the two groups, however, epididymal fat weight was lower in ethanol-fed rats (P = 0.030). Blood glucose, total cholesterol, non-high-density lipoprotein (HDL) and oxidized low-density lipoprotein (LDL) levels were lower in the ethanol group compared to controls (P < 0.05). There was a significant reduction in the expression of hydroxymethylglutaryl-coenzyme A reductase and sterol regulatory element-binding protein-2 in ethanol-treated rats (P < 0.05), suggesting that ethanol may have lowered cholesterol levels via downregulation of genes involved in cholesterol synthesis. Paraoxonase-1, which is associated with inhibition of LDL cholesterol oxidation, was upregulated in the ethanol group (P = 0.029). Ethanol-treated rats exhibited significantly lower levels of high-mobility box group protein 1 (P ≤ 0.05). Cyclooxygenase-2 and RelA gene expression were significantly lower in ethanol-treated rats (P < 0.05), indicating possible anti-inflammatory effects. These findings suggest that moderate ethanol consumption may potentially contribute to improved cardiovascular outcomes by reducing body fat, improving blood cholesterol and blood glucose, and modulation of gene expression involved in inflammation and/or cholesterol synthesis.

Moderate developmental alcohol exposure reduces repetitive alternation in a zebrafish model of fetal alcohol spectrum disorders

The damaging effects of alcohol on a developing fetus are well known and cause a range of conditions known as fetal alcohol spectrum disorder (FASD). High levels of alcohol exposure lead to physical deformity and severe cognitive deficits, but more moderate exposure leads to a range of subtle cognitive effects such as reduced social behavior, higher propensity to develop addictions, and reduced spatial working memory. Previous studies have demonstrated that following exposure to relatively low levels of ethanol during early brain development (equivalent in humans to moderate exposure) zebrafish display a range of social and behavioral differences. Here, our aim was to test the hypothesis that moderate developmental ethanol exposure would affect aspects of learning and memory in zebrafish. In order to do this, we exposed zebrafish embryos to 20 mM [0.12% v/v] ethanol from 2 to 9 dpf to model the effects of moderate prenatal ethanol (MPE) exposure. At 3 months old, adult fish were tested for appetitive and aversive learning, and for spatial alternation in a novel unconditioned y-maze protocol. We found that MPE did not affect appetitive or aversive learning, but exposed-fish showed a robust reduction in repetitive alternations in the y-maze when compared to age matched controls. This study confirms that moderate levels of ethanol exposure to developing embryos have subtle effects on spatial working memory in adulthood. Our data thus suggest that zebrafish may be a promising model system for studying the effects of alcohol on learning and decision-making, but also for developing treatments and interventions to reduce the negative effects of prenatal alcohol.

Acute Ethanol Exposure Promotes Autophagy-Lysosome Pathway-Dependent ASIC1a Protein Degradation and Protects Against Acidosis-Induced Neurotoxicity.

Tissue acidosis is a common feature of brain ischemia which causes neuronal injury. Activation of acid-sensing ion channel 1a (ASIC1a) plays an important role in acidosis-mediated neurotoxicity. Acute ethanol administration has been shown to provide neuroprotective effects during ischemic stroke, but the precise mechanisms have yet to be determined. In this study, we investigated the effect of ethanol on the activity/expression of ASIC1a channels and acidosis-induced neurotoxicity. We showed that acute treatment of neuronal cells with ethanol for more than 3h could reduce ASIC1a protein expression, ASIC currents, and acid-induced [Ca2+]i elevation. We further demonstrated that ethanol-induced reduction of ASIC1a expression is mediated by autophagy-lysosome pathway (ALP)-dependent protein degradation. Finally, we showed that ethanol protected neuronal cells against acidosis-induced cytotoxicity, which effect was mimicked by autophagy activator rapamycin and abolished by autophagy inhibitor CQ. Together, these results indicate that moderate acute ethanol exposure can promote autophagy-lysosome pathway-dependent ASIC1a protein degradation and protect against acidosis-induced neurotoxicity.

Ethanol-induced conformational fluctuations of NMDA receptors

ABSTRACTAlcohol addiction ranks among the leading global causes of preventable death and disabilities in human population. Understanding the sites of ethanol action that mediate its acute and chronic neural and behavioural effects is critical to develop appropriate treatment options for this disorder. The N-methyl-d-asparate (NMDA) receptors are ligand-gated heterotetrameric ion channels, which are known to directly interact with alcohol in a concentration-dependent manner. Yet, the exact molecular mechanisms and conformational dynamics of this interaction are not well understood. Here, we conducted a series of molecular dynamics simulations of the interaction of moderate ethanol concentrations with rat's wild-type GluN1–GluN2B NMDA Receptor under physiological conditions. The simulations suggest that glutamate or glycine alone induce an intermediate conformational state and point towards the transmembrane domain (TMD) as the site of action of ethanol molecules. Ethanol interacts by double hydrogen bonds with Trp635 and Phe638 at the transmembrane M3 helix of GluN2B. Alcohol not only reduces the pore radius of the ion channel within the TMD but also decreases accessibility of glutamate and glycine to the ligand-binding sites by altering the structure of the ligand-binding domain and significantly widening the receptor in that area.

Liquid-hot-water pretreatment of palm-oil residues for ethanol production: An economic approach to the selection of the processing conditions

Liquid Hot Water pretreatment (LHW) was evaluated on empty palm fruit bunch (EPFB) at 160–210 °C, residence time of 0–60 min and solid loadings of 5–25% wt. The effects of these conditions on ethanol yield and potential profit were determined. The “potential profit” was used as response variable to approach the economic feasibility because it helps to dismiss those experiments without economic sense, a task that the yield by itself is not capable. Ethanol yields between 109.6 and 172.1 L/ton dry fed biomass were obtained, the highest ethanol yield was obtained at conditions of 0 min, 5% of solids and 185 °C. Ethanol yield was favored at intermediate temperatures, low residence times and low solid loads. The potential profit was favored at intermediate temperature, lower residence times and high solid loads. The conditions for the optimal ethanol yield did not correspond to the conditions for the optimal potential profit. In fact, the experiment with the highest ethanol yield was not the one with the highest potential profit. Several other experimental conditions that led to moderate ethanol yields exhibited higher potential profits. These higher potential profits are mainly a consequence of higher ethanol concentrations obtained by working with high solid loading, which implies lower distillation costs. The best pretreatment conditions were 30 min, 15% solids and 185 °C because they led to the highest potential profit due to a synergetic effect of a high yield and a high concentration of ethanol.

Impact of Genetic Variation in Aldehyde Dehydrogenase 2 and Alcohol Consumption on Coronary Artery Lesions in Chinese Patients with Stable Coronary Artery Disease.

The aim of this study is to investigate the impact of aldehyde dehydrogenase 2 (ALDH2) genotype and alcohol consumption on coronary artery lesions in Chinese patients with stable coronary artery disease (CAD). A total of 753 Chinese patients (73.6% male) diagnosed with stable CAD by coronary angiography were included in the sample. The frequency of the mutated type ALDH2*2 (including ALDH2*1/*2 and ALDH2*2/*2) was 44.1% in CAD patients. The mutated ALDH2 carriers were more susceptible to multivessel lesions. Low to moderate alcohol consumption is related to higher plasma HDL-C level and fewer coronary artery lesions in CAD patients with ALDH2 wild genotype, while these effects were not observed in CAD patients with ALDH2 mutated genotype. Furthermore, we divided the mutated group into heterozygous and homozygous subgroups, and no obvious relationships were observed among drinking and HDL-C and coronary lesions. To explore the metabolic effects of ALDH2 modified by alcohol, we examined the impact of ALDH2 genotype and alcohol intake on HDL-C levels in ALDH2 wild type and knockout mice. The results showed HDL-C levels were significantly higher post low to moderate alcohol consumption in wild type rather than in knockout mice. CAD patients with mutated ALDH2 genotype are inclined to suffer with coronary artery lesions than wild type subjects. Low to moderate ethanol intake contributes to fewer multivessel lesions in CAD patients with ALDH2 wild type, which might be related to higher HDL-C level.

Brief ethanol exposure and stress-related factors disorganize neonatal breathing plasticity during the brain growth spurt period in the rat

The effects of early ethanol exposure upon neonatal respiratory plasticity have received progressive attention given a multifactorial perspective related with sudden infant death syndrome or hypoxia-associated syndromes. The present preclinical study was performed in 3-9-day-old pups, a stage in development characterized by a brain growth spurt that partially overlaps with the 3rd human gestational trimester. Breathing frequencies and apneas were examined in pups receiving vehicle or a relatively moderate ethanol dose (2.0g/kg) utilizing a whole body plethysmograph. The experimental design also considered possible associations between drug administration stress and exteroceptive cues (plethysmographic context or an artificial odor). Ethanol exposure progressively exerted a detrimental effect upon breathing frequencies. A test conducted at PD9 when pups were under the state of sobriety confirmed ethanol's detrimental effects upon respiratory plasticity (breathing depression). Pre-exposure to the drug also resulted in a highly disorganized respiratory response following a hypoxic event, i.e., heightened apneic episodes. Associative processes involving drug administration procedures and placement in the plethysmographic context also affected respiratory plasticity. Pups that experienced intragastric administrations in close temporal contiguity with such a context showed diminished hyperventilation during hypoxia. In a 2nd test conducted at PD9 while pups were intoxicated and undergoing hypoxia, an attenuated hyperventilatory response was observed. In this test, there were also indications that prior ethanol exposure depressed breathing frequencies during hypoxia and a recovery normoxia phase. As a whole, the results demonstrated that brief ethanol experience and stress-related factors significantly disorganize respiratory patterns as well as arousal responses linked to hypoxia in neonatal rats.

Solubility of the Proteinogenic α-Amino Acids in Water, Ethanol, and Ethanol-Water Mixtures.

The addition of organic solvents to α-amino acids in aqueous solution could be an effective method in crystallization. We reviewed the available data on the solubility of α-amino acids in water, water–ethanol mixtures, and ethanol at 298.15 K and 0.1 MPa. The solubility of l-alanine, l-proline, l-arginine, l-cysteine, and l-lysine in water and ethanol mixtures and the solubility of l-alanine, l-proline, l-arginine, l-cysteine, l-lysine, l-asparagine, l-glutamine, l-histidine, and l-leucine in pure ethanol systems were measured and are published here for the first time. The impact on the solubility of amino acids that can convert in solution, l-glutamic acid and l-cysteine, was studied. At lower concentrations, only the ninhydrin method and the ultraperfomance liquid chromatography (UPLC) method yield reliable results. In the case of α-amino acids that convert in solution, only the UPLC method was able to discern between the different α-amino acids and yields reliable results. Our results demonstrate that α-amino acids with similar physical structures have similar changes in solubility in mixed water/ethanol mixtures. The solubility of l-tryptophan increased at moderate ethanol concentrations.