bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduced Folate Carrier: Tissue Distribution and Effects of Chronic Ethanol Intake in the Micropig
Authors: Villanueva Jesus A. , Devlin Angela M. , Halsted Charles H. 
Published: April 2006

Background: Folate deficiency is common in alcoholic patients, in part due to abnormal transport across membranes relevant to folate homeostasis. The reduced folate carrier (RFC) transports monoglutamyl folates across tissue membranes and could be affected by chronic exposure to ethanol. The micropig model is suitable to study the effect of alcoholism on RFC and folate transport across membranes.Methods: The membrane transport of [3H]‐folic acid was measured by a vacuum filtration method in jejunal brush border (JBB), liver plasma membrane (LPM), and kidney brush border (KBB) membranes vesicles from micropigs fed control or 40% ethanol diets for 12 months. RFC transcripts were analyzed by reverse transcription polymerase chain reaction in jejunal mucosa, liver, and kidney from the same animals.Results: When we compared results from three relevant membranes in control animals, the transport of [3H]‐folic acid was highest in LPM, 3‐fold lower in KBB (p < 0.001), and 6‐fold lower in JBB (p < 0.001). The concentration of RFC transcripts per total RNA was greatest in liver, followed by kidney and jejunum. The transport of [3H]‐folic acid by JBB vesicles from chronic ethanol‐fed animals exhibited 2‐fold lower Km and Vmax (p < 0.05), whereas there was no ethanol effect on the Vmax of [3H]‐folic acid transport by LPM or KBB. RFC transcript levels were 10‐fold lower in jejunal mucosa from ethanol‐fed animals than in control‐fed animals (p < 0.005).Conclusions: Although our findings demonstrate different RFC transcript amounts and transport efficiencies among tissues, the present studies suggest that chronic ethanol exposure decreases the intestinal absorption of folic acid by altering the expression of RFC and consequently its transport kinetics in JBB. These findings provide a mechanism for the clinical finding of reduced folic acid absorption in chronic alcoholics.
Mice That Lack Corticotropin‐Releasing Factor (CRF) Receptors Type 1 Show a Blunted ACTH Response to Acute Alcohol Despite Up‐Regulated Constitutive Hypothalamic CRF Gene Expression
Authors: Lee S. , Smith G. W. , Vale W. , Lee K.‐F. , Rivier C. 
Published: April 2006

Background: The purpose of this work was to determine the influence of acute alcohol treatment, injected intraperitoneally, on the hypothalamic‐pituitary‐adrenal axis of mice that lack type 1 receptor for corticotropin‐releasing factor (CRFR1).Methods: CRFR1‐deficient (CRFR1−/−), heterozygous (CRFR1±), and wild‐type (CRFR1+/+) mice were generated and maintained under standard conditions. Homozygous, heterozygous, and wild‐type offspring were identified by polymerase chain reaction analysis of tail DNA. Experiments were performed on 9‐ to 16‐week‐old male and female mice. All blood samples were obtained by rapid decapitation of conscious mice conducted between 10 AM‐12 PM. Blood sample collection was completed within 20 to 30 sec of disturbing the animals, and all samples were terminal. Preliminary experiments were conducted to determine the time‐course of the ACTH and hypothalamic responses to alcohol in all three groups of mice, and a single time point (30 min and 2 hr, respectively), corresponding to peak responses, was chosen to measure the corresponding parameters in all subsequent studies.Results: In vehicle‐injected animals, basal ACTH and corticosterone levels were statistically comparable in heterozygotes and mice with a null allele for the CRFR1 gene, although values of this latter hormone were slightly lower in the mutants. Alcohol (4.0 g/kg) elicited the expected significant (p < 0.01) increase in plasma ACTH and corticosterone levels in heterozygous mice. These responses were virtually abolished or markedly decreased, respectively, in CRFR1‐deficient animals. As previously reported, constitutive CRF mRNA levels were elevated in the paraventricular nucleus (PVN) of the hypothalamus in mice that lacked CRFR1, compared to wild‐type control mice. Interestingly, this was not the case for transcripts of the immediate early gene NGFI‐B. When measured 2 hr after alcohol, PVN NGFI‐B gene expression was significantly (p < 0.01) increased in both control and mutant mice, as were CRF mRNA levels in mutant mice, but the hypothalamic responses of the mutants were larger (p < 0.01) than those of the control mice. This difference may be due, at least in part, to the lack of steroid feedback in the mutants.Conclusion: These results indicate that although the intraperitoneal injection of alcohol remains capable of eliciting PVN CRF neuronal activation in mice that lack CRFR1, the ACTH and corticosterone responses are significantly blunted, a phenomenon believed to be due to the lack of CRFR1 in the pituitary of these animals.
Enhanced Antioxidant Activity After Chlorination of Quercetin by Hypochlorous Acid
Authors: Binsack Ralf , Boersma Brenda J. , Patel Rakesh P. , Kirk Marion , White C. Roger , Darley‐Usmar Victor , Barnes Stephen , Zhou Fen , Parks Dale A. 
Published: April 2006

Background: Several epidemiological studies indicate that moderate consumption of red wine decreases both the incidence and mortality associated with cardiovascular disease. Quercetin and rutin (quercetin‐3‐rutinoside) are polyphenols present in relatively large concentrations in red wine and may play a role in this cardioprotective phenomenon. The precise mechanisms of cardioprotection remain unclear but may involve the action of these polyphenols as antioxidants, which attenuate the tissue injury that results from the production of proinflammatory oxidants such as hypochlorous acid (HOCl).Methods: To study the interaction of these polyphenols with proinflammatory oxidants, we mixed quercetin or rutin with HOCl (0–150 μM) and analyzed the reaction products by high‐performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance.Results: Stable mono‐ and dichlorinated derivates were detected for both quercetin and the glycoside derivative, rutin, which suggests that both the conjugated and unconjugated forms of quercetin reacted with HOCl similarly. Chlorination of quercetin occurred only at two sites, and the derivates (6‐chloroquercetin, 6,8‐dichloroquercetin) were more potent antioxidants toward oxidative modification of low‐density lipoproteins and ABTS radical formation than the unmodified form.Conclusions: These data suggest that under certain pathological conditions in vivo (e.g., inflammation), flavonols may be converted to chlorinated derivates, which exhibit an enhanced antioxidant potential and thereby play a role in cardioprotection.
Ethanol Enhances GABAA Receptor Function in Short Sleep and Long Sleep Mouse Brain Membranes
Authors: Davies Daryl L. , Alkana Ronald L. 
Published: April 2006

Background: SS and LS mice have been used to explore the genetic and neurochemical bases for differences in sensitivity to ethanol. The present study investigated the effects of ethanol on GABAA receptor function in microsacs from these genotypes. The purpose was to test a key element of the hypothesis that differences between these lines in sensitivity to ethanol‐induced enhancement of GABAA receptor function underlie their selected differences in sensitivity to ethanol‐induced loss of righting reflex (LORR).Methods: The effects of ethanol on GABA‐activated 36Cl− uptake in brain membranes (microsacs) isolated from male SS and LS mice were tested using a chloride flux filtration assay.Results: Ethanol significantly enhanced GABA‐activated 36Cl− uptake in SS microsacs at concentrations of 100–300 mM. Ethanol did not significantly affect GABA‐activated chloride uptake in this preparation at concentrations of 25 and 50 mM. Ethanol significantly enhanced GABA‐activated 36Cl− uptake in LS microsacs at concentrations of 25–100 mM, but not at 200 mM.Conclusion: The present studies are the first to show a statistically significant effect of ethanol on GABA‐activated chloride uptake in both SS and LS mice with a clear difference between the genotypes in threshold. The relative threshold differences between SS and LS microsacs in sensitivity to ethanol indicate that selection for resistance to ethanol‐induced LORR in SS mice has shifted the ethanol‐GABAA receptor concentration‐response curve to the right. The findings add key evidence that supports a cause‐effect relationship between sensitivity to ethanol‐induced potentiation of GABAA receptor function and genetically determined sensitivity to ethanol's behavioral effects.
Influence of Age, Sex, and Helicobacter pylori Infection Before and After Eradication on Gastric Alcohol Dehydrogenase Activity
Authors: Kechagias Stergios , Jönsson Kjell‐Åke , Borch Kurt , Jones Alan Wayne 
Published: April 2006

Background: Gastric alcohol dehydrogenase may contribute to the metabolism of orally ingested ethanol and decrease the bioavailability of the drug. The aims of this study were to assess the impact of Helicobacter pylori infection and its eradication on gastric alcohol dehydrogenase activity and to relate the findings to gastric histology. Furthermore, the role of age‐ and sex‐related differences in gastric alcohol dehydrogenase activity were studied.Methods: A total of 76 subjects (39 women and 37 men) underwent upper gastrointestinal endoscopy, and biopsies were obtained from the corpus and antrum. The specimens were used for determining gastric alcohol dehydrogenase activity, histological examination, and urease testing. Subjects with H. pylori infection (n= 36) received medication to eradicate the infection, and repeat biopsies were taken 2 and 12 months later.Results: No significant difference in gastric alcohol dehydrogenase activity was found between men and women (p > 0.05). Gastric alcohol dehydrogenase activity did not differ significantly between the subjects older than 50 years (n= 39) and those 50 years or younger (n= 37). In subjects with H. pylori infection, gastric alcohol dehydrogenase activity was significantly reduced in the antrum (p < 0.05). After eradication of H. pylori, alcohol dehydrogenase activity in the antrum increased significantly within 2 months (p < 0.01). Antral biopsies with the most pronounced inflammation and histological changes had significantly decreased alcohol dehydrogenase activity (p < 0.05). In contrast, no significant differences were found in corpus.Conclusions: H. pylori infection is associated with decreased antral alcohol dehydrogenase activity, which seems to be related to the severity of the inflammatory changes in the mucosa. Eradication of H. pylori normalizes antral alcohol dehydrogenase activity within 2 months.
Visual P3 in Female Alcoholics
Authors: Prabhu V. Radha , Porjesz Bernice , Chorlian David B. , Wang Kongming , Stimus Arthur , Begleiter Henri 
Published: April 2006

Background: The P300 (P3) component of the event related potential has been established as a sensitive risk marker of vulnerability to alcoholism. Most alcoholism studies have focused on men; recent studies indicate that women are equally vulnerable to developing alcoholism.Methods: Visual P3 recorded from 31 electrode positions was evaluated in 44 alcoholic and 60 control women, 24–50 years of age. P3 amplitudes and latencies of the two groups were statistically compared using Analysis of Variance; source localization of surface amplitude values from each group were plotted using a low‐resolution brain electromagnetic tomography.Results: The results indicated that alcoholic women had significantly smaller P3 amplitudes in the frontal and central regions compared with controls. Source localization showed lowered activation in alcoholic women in right dorso‐lateral prefrontal cortex and the ventro‐medial fronto‐central regions.Conclusions: The results suggest that P3 is an equally sensitive endophenotypic marker of vulnerability to alcoholism in women. The findings are discussed in terms of functional and physiologic significance of the P3 amplitude in alcoholic women and its relationship to drinking behaviors.
Individual Differences in Responses to Ethanol and d‐Amphetamine: A Within‐Subject Study
Authors: Holdstock Louis , de Wit Harriet 
Published: April 2006

Background: In some individuals, ethanol (EtOH) produces marked stimulant‐like subjective effects resembling those of stimulant drugs, like d‐amphetamine (AMP). In this study, we examined the neurochemical basis of these individual differences by examining the same subjects’ responses to both EtOH and AMP. A positive correlation between subjects’ responses to the two drugs may suggest that AMP and EtOH produce their stimulant‐like subjective effects by a shared mechanism.Methods: Twenty‐seven volunteers (17 male, 10 female), aged 21–35, received beverages or capsules containing EtOH 0.8 g/kg, AMP 10 or 20 mg, or placebo on four separate sessions in random order and under double‐blind conditions. Various self‐reported and objective drug effects were measured, including measures sensitive to subjective and cognitive stimulant‐like effects.Results: EtOH and AMP produced their prototypical subjective and behavioral effects, including increased ratings of stimulant‐like subjective effects, increased heart rate and blood pressure, and improved vigilance performance after AMP and increased ratings of sedative‐like subjective effects, increased heart rate and blood pressure, and impaired vigilance performance after EtOH. Consistent with previous reports, there was substantial intersubject variability in subjective responses to EtOH: some subjects reported primarily stimulant‐like effects, whereas others reported primarily sedative‐like effects. To examine the relationship between these responses to EtOH and subjects’ responses to AMP, correlations were examined between effects of EtOH and AMP. For all subjects together, there was a significant positive correlation between responses to EtOH and 20 mg AMP on the ARCI A scale (a measure of stimulant‐like subjective effects;r= 0.41, p < 0.05). Among only those subjects who reported primarily stimulant‐like effects from EtOH, the correlation between EtOH and AMP was 0.64 (p < 0.05).Conclusions: Subjects who experience pronounced stimulant‐like effects from EtOH also report greater stimulant effects from AMP, suggesting that these effects may be mediated through similar mechanisms. These correlations between the drugs’ effects were not observed on other measures, such as DSST or vigilance task performance or heart rate. This may indicate that these other effects are mediated by separate mechanisms. The study illustrates a novel approach to studying the neurochemical basis of drug effects.
Sex and Strain Differences in Ethanol Drinking: Effects of Gonadectomy
Authors: Cailhol Stéphanie , Mormède Pierre 
Published: April 2006

Background: Alcohol drinking behavior in rats is known to be sexually dimorphic and strain‐dependent.Methods: To test whether the gonadal steroid milieu exerts activational effects on ethanol intake and can modulate individual sensitivity toward alcohol use and misuse, we examined the effects of gonadectomy on oral self‐administration (OSA) of ethanol in male and female rats from different strains. After castration, animals were given continuous free choice between water and ethanol solutions. The ethanol concentration was progressively increased from 2% to 10% and maintained at 6% (the preferred concentration) for 24 days. Ethanol solutions were then withdrawn for 9 days. During the second phase of free‐choice drinking, the ethanol concentration was gradually increased every 4 days by the following amounts, in order as listed: 6%, 12%, and 24%.Results: Our results confirm both gender and strain differences in ethanol drinking: females exhibited higher ethanol intake than males, and the WKHA strain drank more than the WKY and SHR strains. However, except for a small decrease in ethanol drinking during the acquisition of ethanol OSA in males after castration, no clear‐cut difference was found between gonadectomized and sham‐operated animals during the maintenance of ethanol OSA behavior.Conclusions: These data suggest that gender and strain differences observed are insensitive to gonadal steroids during adulthood, and that different sensitivities to the effect of gonadal steroids do not explain the sex × strain interaction observed in ethanol drinking.
Zinc Supplementation Does Not Attenuate Alcohol‐Induced Cerebellar Purkinje Cell Loss During the Brain Growth Spurt Period
Authors: Chen Wei‐Jung A. , Berryhill Eve C. , West James R. 
Published: April 2006

Background: Alcohol‐induced zinc deficiency is one of the mechanisms proposed as a cause of developmental brain damage associated with fetal alcohol syndrome. It is known that alcohol exposure during the brain growth spurt period leads to cerebellar Purkinje cell loss. Therefore, this study examined whether zinc supplementation was capable of preventing alcohol‐induced Purkinje cell loss in the cerebellar vermis in a neonatal rat model system.Methods: Sprague‐Dawley rat pups were given alcohol (EtOH; 4.5 g/kg/day), zinc (Zn; 0.54 mg/ml diet; [10 times the regular diet Zn concentration]), or both from postnatal days (PD) 4 through 9 using the artificial‐rearing paradigm. A gastrostomy control (GC) and a suckle control group (SC) also were included. All pups were killed on PD 10. Following perfusion, the cerebellar vermis was dissected and processed for stereological cell counting. The total number of Purkinje cells and the volume of the cerebellar vermis were determined.Results: Alcohol produced a significant loss of Purkinje cells compared with that in the GC group (no EtOH and no Zn supplement). The zinc supplementation had no effect in attenuating alcohol‐induced Purkinje cell loss in the cerebellar vermis. In fact, the serum zinc concentration data indicated higher zinc concentrations following either EtOH or Zn treatment. Interestingly, the GC group showed a significantly lower zinc concentration compared with the SC group, even though no significant difference in Purkinje cell numbers was observed between these two control groups.Conclusion: These findings indicate that alcohol exposure during the third trimester equivalent did not result in zinc deficiency in this neonatal rat model system, nor did zinc supplementation rescue the alcohol‐induced Purkinje cell loss in the cerebellar vermis. These findings showed clearly that the serum zinc concentration was not correlated with Purkinje cell loss, suggesting that alcohol‐induced loss of cerebellar Purkinje cells in this neonatal rat model system is independent of the availability of serum zinc.
Removal of Glutathione Produces Apoptosis and Necrosis in HepG2 Cells Overexpressing CYP2E1
Authors: Wu Defeng , Cederbaum Arthur I. 
Published: April 2006

Background: Previous studies have shown that addition of ethanol, iron, or arachidonic acid to HepG2 cells expressing CYP2E1 produced a loss in cell viability and caused apoptosis. These effects were enhanced when cellular reduced glutathione (GSH) levels were lowered by treatment with buthionine sulfoximine (BSO). Overexpression of CYP2E1 in HepG2 cells could produce toxicity even in the absence of added toxin after BSO treatment. Studies were carried out to characterize this CYP2E1‐and BSO‐dependent toxicity.Methods: HepG2 cells expressing CYP2E1 were treated with BSO for 1 to 4 days, and various parameters associated with apoptosis and cell viability were assayed.Results: Treatment of cells expressing CYP2E1 (E47 cells) with BSO resulted in apoptosis as well as necrosis. The apoptosis and necrosis were independent of each other. No toxicity was found with control HepG2 cells or HepG2 cells expressing CYP3A4 instead of CYP2E1 under these conditions. The antioxidant trolox partially prevented the apoptosis and necrosis, whereas diallylsulfide, a CYP2E1 inhibitor, was fully protective. The activity of caspase 3, but not caspases 1, 8, or 9, was increased in the BSO‐treated E47 cells, and an inhibitor of caspase 3 prevented apoptosis. Damage to mitochondria appears to play a role in the CYP2E1‐ and BSO‐dependent toxicity, because mitochondrial membrane potential was decreased and cyclosporin A, an inhibitor of the mitochondrial membrane permeability transition, prevented the apoptosis and the necrosis. The fall in membrane potential was prevented by trolox and diallylsulfide, suggesting damage to the mitochondria by CYP2E1‐derived reactive oxygen species.Conclusions: These results indicate the critical role of GSH in protecting against CYP2E1‐mediated oxidative stress and that mitochondria may be a target for CYP2E1‐derived reactive oxygen species, and suggest that interactions between CYP2E1, mitochondria, and altered GSH homeostasis may play a role in alcohol‐induced liver injury.
Gene‐Environment Interaction in Patterns of Adolescent Drinking: Regional Residency Moderates Longitudinal Influences on Alcohol Use
Authors: Rose Richard J. , Dick Danielle M. , Viken Richard J. , Kaprio Jaakko 
Published: April 2006

Background: Drinking frequency escalates rapidly during adolescence. Abstinence declines markedly, and drinking monthly or more often becomes normative. Individual differences in adolescent drinking patterns are large, and some patterns are predictive of subsequent drinking problems; little, however, is known of the gene–environment interactions that create them.Methods: Five consecutive and complete birth cohorts of Finnish twins, born 1975–1979, were enrolled sequentially into a longitudinal study and assessed, with postal questionnaires, at ages 16, 17, and 18.5 years. The sample included 1786 same‐sex twin pairs, of whom 1240 pairs were concordantly drinking at age 16. Maximum likelihood models were fit in longitudinal analyses of the three waves of drinking data to assess changes in genetic and environmental influences on alcohol use across adolescence. Secondary analyses contrasted twin pairs residing in rural versus those in urban environments to investigate gene–environment interactions.Results: Longitudinal analyses revealed that genetic factors influencing drinking patterns increased in importance across the 30‐month period, and effects arising from common environmental influences declined. Distributions of drinking frequencies in twins residing in urban and rural environments were highly similar, but influences on drinking varied between the two environments. Genetic factors assumed a larger role among adolescents residing in urban areas, while common environmental influences were more important in rural settings. Formal modeling of the data established a significant gene–environment interaction.Conclusions: The results document the changing impact of genetic and environmental influences on alcohol use across adolescence. Importantly, the results also reveal a significant gene–environment interaction in patterns of adolescent drinking and invite more detailed analyses of the pathways and mechanisms by which environments modulate genetic effects.