bluuebunny/crossref_metadata_2025 huggingface dataset:
Polymorphism of Alcohol‐Metabolizing Genes Affects Drinking Behavior and Alcoholic Liver Disease in Japanese Men
Authors: Tanaka Furnika , Shiratori Yasushi , Yokosuka Osarnu , Imazeki Furnio , Tsukada Yoshio , Omata Masao
Published: May 2006

Alcohol is known to be mainly metabolized in the liver by alcohol dehydrogenase 2 (ADH2) and aldehyde dehydrogenase 2 (ALDH2), and cytochrome P‐45011EI. The purpose of this study was to clarify the role of polymorphism of these ethanol‐metabolizing enzymes in drinking behavior and the progression of alcoholic liver disease among Japanese men. Polymorphism of the ADH2, ALDH2, and P‐45011EI genes was determined by polymerase chain reaction, followed by restriction fragment‐length polymorphism analysis in 189 normal Japanese men and 26 male patients with alcoholic liver disease. Drinking behavior was estimated by self‐assessment according to DSM‐Ill‐R criteria. Facial flushing was reported in 91 subjects heterozygous for ALDH2*1/*2 and in two subjects homozygous for ALDH2*2/*2, but was not found in 96 subjects homozygous for ALDH2*1/*1. In contrast, polymorphism of ADH2 and P‐45011EI did not differ between flushers and nonflushers. Although the flushers only drank a small amount of alcohol (<20 g of ethanoVday), the nonflushers were divided into a group of moderate drinkers (20 to 80 glday; n = 54) and a group of heavy drinkers (780 g/day; n= 42). A high preponderance of heterozygosity for the ADH2*1/*2 genes (29/ 42; 69%) and a high frequency of the ADH2*1 allele were found in heavy drinkers, compared with moderate drinkers. However, cytochrome P‐45011EI gene polymorphism was similar among the moderate and heavy drinkers. Not only a high frequency of the ALDHPl and ADH2*1 alleles, but also a high frequency of the P‐45011EI c2 allele was found in the patients with alcoholic liver disease. From these results, the drinking behavior of Japanese men is strongly influenced by the ALDH2*l allele, and the level of alcohol intake is affected by the ADH2*1 allele, but not by cytochrome P‐45011EI. However, progression to alcoholic liver disease among heavy drinkers may be affected by the cytochrome P‐45011EI c2 allele.
Interactions Between Alcohol‐ and Opioid‐Induced Suppression of Rat Testicular Steroidogenesis In Vivo
Authors: Adams Michael L. , Meyer Edward R. , Cicero Theodore J.
Published: May 2006

To examine interactions between alcohol and endogenous opioids in their suppressive effects on rat testicular function, the opioid antagonist naltrexone or the opioid agonist morphine was administered to adult male rats alone or in combination with alcohol. Serum testosterone, testicular interstitial fluid (TIF) testosterone, and TIF volumes were measured to assess testicular function. Naltrexone induced dose‐dependent increases in serum and TIF testosterone levels without changes in TIF volume. Alcohol (0.5 g/kg) inhibited naltrex‐one‐induced stimulation of testosterone secretion and shifted the naltrexone dose‐response curve to the right. Conversely, naltrexone (0.05 mg/kg) inhibited alcohol‐induced suppression of testosterone secretion and shifted the alcohol dose‐response curve to the right. Relatively high doses of naltrexone (5 to 30 mg/kg) were needed to stimulate testosterone secretion maximally in rats treated with a low dose of alcohol (0.5 g/kg) and to stimulate normal levels of testosterone secretion in rats treated with a high dose of alcohol (2 g/kg). In addition, combined treatment with 1 and 30 mg/kg of naltrexone and 0.5 to 2 g/kg of alcohol did not alter blood alcohol concentrations significantly, suggesting that the interactions between alcohol and naltrexone were unrelated to gross changes in alcohol metabolism or bioavailability factors. Simultaneous treatments with a low dose of alcohol (0.3 g/kg), near the threshold of efficacy, and low‐moderate doses of morphine (0.3 to 3 mg/kg) were not additive in suppressing testosterone secretion, compared with either agent alone. These results support the hypothesis that opioid antagonists can reverse the suppressive effect of alcohol on testicular steroidogenesis, but the results also suggest that endogenous opioids do not exclusively mediate alcohol's effects on testosterone secretion.
Naltrexone Effects on Ethanol Drinking Acquisition and on Established Ethanol Consumption in C57BL/6J Mice
Authors: Phillips Tamara J. , Wenger Charlotte D. , Dorow Janet D.
Published: May 2006

Naltrexone's success as a treatment agent for alcoholism seems to be due to its ability to reduce craving in abstinent, dependent individuals and to reduce the pleasure associated with subsequent intake. However, more study is needed to establish the optimal amount of time that naltrexone treatment should be continued. Little information seems to have been collected regarding the most effective dosing regimen for reducing alcohol craving and consumption, and the usefulness of opiate antagonists in the prevention of alcohol dependence in nonaddicts, rather than just as a treatment agent in addicted individuals, also deserves further study. The alcohol‐preferring C57BL/6J (B6) mice were used to: (1) study naltrexone effects on consumption in established drinkers using an increasing dosing regimen, (2) study naltrexone effects on the acquisition of ethanol drinking, and (3) study the effects of chronic naltrexone from timed‐release pellets on drinking in alcohol‐naive mice. Naltrexone reduced ethanol preference in established drinkers, but its effects waned at increasing doses. Naltrexone slowed the acquisition of ethanol drinking, but was ineffective when readministered after a phase when ethanol was offered in the absence of naltrexone. Mice with chronic naltrexone pellets consumed greater amounts of ethanol and showed higher ethanol preference than did placebo‐pelleted animals. The observed reduced efficacy of naltrexone with increasing dosage and chronic treatment may have been due to naltrexone‐induced opiate receptor changes. Such changes are presumably more likely to occur when naltrexone doses remain high or perhaps accumulate. Thus, dose and frequency of administration may be important factors in determining naltrexone's effectiveness in treating alcohol dependence.
The Role of cAMP in Ethanol‐Regulated β‐Endorphin Release from Hypothalamic Neurons
Authors: Boyadjieva Nadka Iv. , Sarkar Dipak K.
Published: May 2006

We have previously shown that ethanol acutely stimulates immuno‐reactive β‐endorphin (IR‐β‐EP) release from hypothalamic neurons, whereas chronic administration of ethanol desensitizes these neurons. In the study reported herein, the role of the intracellular cAMP system in the ethanol‐regulated IR‐β‐EP release from hypothalamic cells in primary cultures was investigated. Acute treatment with ethanol or with the cAMP analog, dibutyryl cAMP, revealed that both agents stimulate the release of IR‐β‐EP from the hypothalamic cells. Combined treatment of ethanol and the cAMP analog produced a synergistic effect on IR‐β‐EP release. Treatment with ethanol and a cAMP‐elevating agent, forskolin, increased cAMP levels in cultured hypothalamic cells. However, prior exposure to ethanol reduced the cAMP‐elevating responses of these neurons to ethanol and forskolin. These results indicate that the stimulatory and adaptive responses of IR‐β‐EP neurons to ethanol may involve the cAMP system.
Ethanol‐Reinforced Responding by AA and ANA Rats Following the Sucrose‐Substitution Initiation Procedure
Authors: Files Forrest J. , Denning Charles E. , Hyytia Petri , Kiianmaa Kalervo , Samson Herman H.
Published: May 2006

Ethanol‐reinforced responding was initiated in male AA and ANA rats using the sucrose‐substitution procedure. Before the initiation procedure, a homecage, two‐bottle preference test was conducted. The rats were then trained to respond on an Fixed‐Ratio 1 schedule with sucrose reinforcement. Over sessions, ethanol was added gradually to the sucrose solution as the concentration of sucrose was reduced until 10% ethanol (v/v) alone functioned as the reinforcer for lever pressing. The schedule of reinforcement was then increased to Fixed‐Ratio 4. Next, the ethanol concentration presented as the reinforcer was increased over weeks to 15%, 20%, 30%, and then returned to 10%. A second homecage test was then performed. The results showed that the AA and ANA lines differed significantly on preference and intake (g/kg) during the homecage preference tests. There was a significant increase in preference during the second homecage test. During sucrose substitution, initial large differences in responding were observed between the lines. When the ethanol concentration was increased, intake (grams per kilogram) increased for the AA line but not for the ANA line. These effects were a function of no change in responding by the AA rats as concentration was increased and a decrease in responding by the ANA rats at the higher concentrations (20% and 30%). Taken together, data indicate that ethanol can function as a positive reinforcer for the behavior of AA and ANA rats. Even though 10% ethanol functioned as a reinforcer similarly for the two lines, ethanol intake in the AA line was significantly greater at the higher concentrations of ethanol, suggesting that ethanol functioned as a qualitatively different reinforcer for the AA rats, compared with the ANA rats.
Characterization of the μ and δ Opioid Receptors in the Brain of the C57BL/6 and DBA/2 Mice, Selected for Their Differences in Voluntary Ethanol Consumption
Authors: de Waele Jean‐Pascal , Gianoulakis Christina
Published: May 2006

Genetically determined differences in the activity of the hypothalamic β‐endorphin system have been demonstrated between the C57BL/6 (alcohol‐preferring) and DBA/2 (alcohol‐aversive) inbred strains of mice. The present studies examined the distribution and density of the μ and δ receptors in specific brain regions that may mediate the rewarding and reinforcing effects of ethanol, using quantitative auto‐radiography and the specific μ agonist FK 33–824 and 6 agonist DPDPE, in their iodinated form. 125I‐FK 33–824 recognizes a high affinity binding site in brain membrane preparations from both the C57BL/6 (Kd= 1.37 ± 0.22 nM; Bmax= 80 ± 12.3 fmol/mg protein) and DBA/2 mice (Kd= 1.02 ± 0.16 nM; Bmax= 39.5 ± 9.6 fmol/mg protein), whereas 125I‐DPDPE binds to a high affinity binding site in brain membranes from both the C57BL/6 (Kd= 1.08 ± 0.34 nM; Bmax= 24.4 ± 4.5 fmol/mg protein) and DBA/2 mice (Kd= 0.68 ± 0.24 nM; Bmax= 15.3 ± 3.7 fmol/mg protein). The auto‐radiographic studies demonstrated differences in the density of the μ opioid receptors between the two strains of mice in brain nuclei that are not directly related to the brain reward system. However, strain‐related differences in the density of δ opioid receptors were observed in regions of the limbic system known to mediate the positive reinforcing effects of many drugs of abuse. The density of δ receptors was significantly higher in the ventral tegmental area and nucleus accumbens of the C57BL/6 mice. The results of the present study support the hypothesis that genetically determined differences exist in the density of opioid receptors in distinct regions of the brain between the C57BL/6 and DBA/2 inbred strains of mice, which may play a role in controlling their voluntary ethanol consumption.
Effects of Prenatal and Early Postnatal Ethanol Exposure on [3H]MK‐801 Binding in Rat Cortex and Hippocampus
Authors: Dim‐Granados J. L. , Spuhler‐Phillips K. , Lilliquist M. W. , Amsel A. , Leslie S. W.
Published: May 2006

The effects of prenatal and/or early postnatal exposure to ethanol at high concentrations on N‐methyl‐D‐aspartate (NMDA) receptor number and functioning in the weanling rat were examined. The bingelike exposure protocol was used in an animal model of acute ethanol effects at two critical periods of development. [3H]MK‐801 binding parameters for the internal channel phencyclidine site were assessed in the presence of 10 μM glutamate and 10 μM glycine activation. Four treatment groups were included: (1) animals exposed to ethanol both prenatal and postnatal; (2) animals exposed only prenatal; (3) animals exposed early postnatal only; and (4) control animals with no exposure to ethanol. The results of the [3H]MK‐801 binding experiments showed that both prenatal and postnatal exposure to ethanol resulted in a significant decrease in the density of NMDA receptors. In addition, data indicated an apparent increase in the percentage of high‐affinity state (open channel state) relative to low‐affinity state (close channel state) receptors in the ethanoltreated groups. These results show that both prenatal and postnatal ethanol exposure decrease NMDA receptor density in the cortex and hippocampus. The findings are consistent with previous observations by our laboratory and others that NMDA‐mediated calcium influx is reduced in these regions, as well as in whole brain by prenatal ethanol exposure. It is suggested that after ethanol exposure, the remaining functional NMDA receptors might have altered sensitiviity to coagonist activation with an increased probability of channel opening.
Alcohol‐Induced Regulation of Nuclear Regulatory Factor‐Kβ in Human Monocytes
Authors: Mandrekar Pranoti , Catalano Donna , Szabo Gyongyi
Published: May 2006

Acute ethanol exposure has the capacity to modulate immune functions, particularly, to down regulate monocyte production of inflammatory cytokines. However, the intracellular mechanisms for these effects of ethanol are yet to be understood. Considering that nuclear regulatory factor‐kβ (NF‐KB)/Rel is a common regulatory element of the promoter region of the inflammatory cytokine genes, herein, we tested the hypothesis that acute ethanol affects NF‐kB activation in human monocytes. Adherence‐isolated monocytes showed constitutive DNA binding activity of NF‐kB. A clinically relevant dose (25 mM) of acute ethanol treatment in vitro increased NF‐kB binding activity in monocytes with a preferential induction of the inhibitory, p50/p50, NF‐kB/Rel homodimer, and resulted in no induction of the p65/p50 heterodimer. In contrast, lipopolysaccharide stimulation primarily induced the p65/p50 heterodimer that has been shown to result in gene activation. Thus, such unique activation of the inhibitory p50/p50 homodimer by acute ethanol treatment may result in inhibition rather than activation of NF‐kB‐regulated inflammatory cytokine genes. Consequently, these results suggest that physiologically relevant concentrations of ethanol may affect production of inflammatory cytokines, such as tumor necrosis factor‐α, interleukin‐1β, and interleukin‐6 by disrupting NF‐kB signaling in monocytes.
Ethanol‐Induced Changes in Prostaglandin E Concentration in the Intact Cerebral Cortex of Preterm and Near‐term Fetal Sheep
Authors: Reynolds James D. , Penning Donald H. , Kimura Karen A. , Dexter Franklin , Henderson Janice L. , Atkins Barry , Poduska Daniel , Brien James F.
Published: May 2006

Ethanol‐induced changes in fetal prostaglandin E (PGE) concentration may play a role in the toxic effects of prenatal ethanol exposure. Using the novel technique of in utero microdialysis, the present study tested the hypothesis that acute ethanol exposure changes PGE concentration in the intact cerebral cortex of preterm (93 ± 1 days of gestation) and near‐term (124 ± 1 days of gestation; term, ∼147 days) fetal sheep. Fetal sheep were surgically instrumented with a microdialysis probe placed in the parasagittal parietal cortex. Three days later, the effects of maternal infusion of 1 g of ethanol/kg maternal body weight on preterm (n= 6) and near‐term (n = 7) fetal cerebral cortical and plasma PGE concentrations were determined. In the preterm fetal cerebral cortex, PGE concentration was increased after ethanol infusion in all six animals studied. The median peak increase was 160% with a 95% confidence interval of 115 to 784%. There was considerable variation in the time of occurrence, magnitude, and duration of this increase. In the near‐term fetal cerebral cortex, an increase in PGE concentration was observed after ethanol infusion in 5 of the 7 animals studied, whereas a decrease in PGE concentration was observed in the other two animals. Overall, ethanol did not increase significantly near‐term fetal cerebral cortical PGE concentration. For both age groups, ethanol infusion had no effect on fetal plasma PGE concentration. These data indicate that ethanol can affect PGE production in the fetal cerebral cortex and that this effect seems to be gestational‐age‐dependent.
Involvement of Catecholamines and Glucocorticoids in Ethanol‐Induced Suppression of Splenic Natural Killer Cell Activity in a Mouse Model for Binge Drinking
Authors: Wu Wen‐Jun , Pruett Stephen B.
Published: May 2006

Ethanol (EtOH) suppresses splenic natural killer (NK) cell activity in a mouse binge drinking model. Direct effects of EtOH and its metabolites are not the major cause of this suppression. Also, catecholamines do not completely explain this suppression. This implicates the involvement of other neuroendocrine mediators in this suppression. Previous studies in this laboratory have shown that RU 486 at a dosage of 100 mg/kg did not affect EtOH‐induced suppression of NK cell activity. However, in the present study, RU 486 at a dosage of 200 mg/kg partially blocked the suppression of NK cell activity induced by EtOH. Moreover, corticosterone at levels expected in the free (unbound) form in EtOH‐treated mice decreased NK cell activity in vitro. Nadolol in combination with RU 486 blocked the suppression of NK cell activity in EtOH‐treated mice. Although there were reasons to suspect that EtOH‐induced changes in the levels of growth hormone or prolactin might also contribute to the suppression of NK cell activity; evidence obtained herein did not indicate such involvement Thus, glucocorticoids and catecholamines seem to be involved in EtOH‐induced suppression of NK cell activity. Together, with the direct effects of EtOH, these neuroendocrine mediators seem to be sufficient to explain all of the suppression of NK cell activity caused by EtOH.
Changes in Oral Ethanol Self‐Administration Patterns Resulting from Ethanol Concentration Manipulations
Authors: Slawecki Craig J. , Samson Herman H.
Published: May 2006

A variety of initiation procedures have been used to develop oral ethanol consumption. Using the sucrose‐substitution procedure, oral self‐administration of ethanol‐water solutions with ethanol concentrations as high as 40% can be initiated in food‐ and fluid‐sated rats. An important question for these models is the relationship between ethanol concentration and self‐administration patterns after initiation. This study examined the differential patterns of ethanol self‐administration maintained by a range of ethanol solutions (10 to 30%) over a 5‐week period, compared with rats maintained on 10% ethanol for 5 weeks. In 43 male Long Evans rats, the sucrose‐substitution procedure was used to initiate responding maintained by 10% ethanol on a Fixed Ratio 4 schedule of reinforcement. The ethanol concentration presented was then increased to 30% in step‐wise fashion and then returned to 10% [Ethanol Concentration Manipulation (ECM) group, n= 32], or 10% ethanol was maintained as the reinforcer for 5 weeks [Control (Con) group, n = 11]. Significant increases in ethanol intake and decreases in responding were associated with increased ethanol concentration. Although no overall differences in total session responding were observed in either group between week 1 and week 5 (10E vs. 10E), examination of changes in initial low responders of the ECM group revealed significant increases in responding that were not observed in the initial low responders of the Con group. Significant increases in momentary response rates were observed on both the ECM and Con groups, independent of the ethanol concentration presented. Increases in response rate in the ECM group were the result of increases in initial low rate and high rate responders; however, the increased response rabs in the Con group were the result of increases only in the initial low rate responders. These data suggest that the ECM procedure can aid in the initiation of ethanol self‐administration and may be particulafly useful in rats of heterogeneous stock.
Differential Sensitivity of Human Neuroblastoma Cell Lines to Ethanol: Correlations with Their Proliferative Responses to Mitogenic Growth Factors and Expression of Growth Factor Receptors
Authors: Luo Jia , Miller Michael W.
Published: May 2006

Early ethanol exposure depletes neurons in the developing nervous system, however the effects on neuronal precursors are not homogeneous. Some cells are more susceptible to ethanol toxicity than others. Growth factors are important mitogens for neuronal precursors. We tested the hypothesis that the differential sensitivity of neuronal precursors to ethanol is determined by their responses to growth factors using an in vitro model (SH‐SY5Y, SK‐N‐SH, and IMR32 neuroblastoma cells) of neuronal precursors. The three cell lines were raised in a medium containing 10% or 0% fetal calf serum. Cells were exposed to ethanol and/or a growth factor. These factors included basic fibroblast growth factor, epidermal growth factor, insulin‐like growth factor‐l, nerve growth factor, and platelet‐derived growth factors AA and BB. The numbers of cells per culture were counted both before and after 3 days of ethanol and/or growth factor treatment. In addition, the effect of ethanol exposure on the expression of receptors for these growth factors was examined. Neuroblastoma cells displayed differential sensitivity to ethanol. The growth of SH‐SY5Y and SK‐N‐SH cells was inhibited by ethanol in a concentration‐dependent manner. Ethanol did not affect cell viability. Thus, this inhibition resulted from a reduction of cell proliferation. In contrast, IMR32 cells were not affected by ethanol (even at concentrations as high as 800 mg/dl). The response to growth factors was also heterogeneous. In serum‐supplemented medium, SH‐SY5Y and SK‐N‐SH cells were stimulated by all of the tested growth factors. For cells raised in a serum‐free medium, only the nerve growth factor was ineffective. IMR32 cells, however, were unaffected by most of these growth factors, regardless of the medium conditions. Ethanol blocked the action of all growth factors tested. In general, all cells expressed the specific receptors for the six growth factors. Only the expression of the basic fibroblast growth factor, insulin‐like growth factor‐l, and nerve growth factor receptors were reduced by ethanol exposure. In summary, neuroblastoma cells exhibit differential susceptibility to ethanol, and this correlates with their response to mitogenic growth factors. Some growth factors are a target of ethanol toxicity. These heterogeneous effects seem to parallel ethanol‐induced changes of proliferating neuronal precursors in vivo.
Ethanol Feeding Inhibits Proinflammatory Cytokine Expression from Murine Alveolar Macrophages Ex Vivo
Authors: Standiford Theodore J. , Danforth Jean M.
Published: May 2006

The prolonged and excessive consumption of alcohol has been shown to predispose the host to a variety of infectious complications, which may be due, in part, to the inability to produce important activating and chemotactic cytokines. In this study, we assessed the effect of alcohol ingestion on the expression of tumor necrosis factor‐α (TNF‐α), and the chemokines macrophage inflammatory protein‐2 (MIP‐2) and macrophage inflammatory protein‐1α (MIP‐1α) from murine alveolar macrophages (AMs) cultured ex vivo. Two‐week ethanol feeding resulted in substantial impairment in the lipopolysaccharide (LPS)‐induced expression of TNF‐α, MIP‐2, and MIP‐1α mRNA, and protein from LPS‐stimulated AMs, compared with cytokine production from AMs obtained from CD‐1 mice receiving an isocaloric control diet. These findings indicate that ethanol feeding results in diminished production of chemotactic and/or activating cytokines from AMs ex vivo that may contribute to the impairment in lung inflammatory responses and antimicrobial host defense that is observed in the setting of alcohol ingestion/intoxication clinically and experimentally.
Endocrine and Hemodynamic Effects of Stress Versus Systemic CRF in Alcoholics during Early and Medium Term Abstinence
Authors: Ehrenreich Hannelore , Schuck Jörg , Stender Nike , Pilz Jürgen , Gefeller Olaf , Schilling Lothar , Poser Wolfgang , Kaw Semiko
Published: May 2006

In alcoholics, disturbances of the autonomie nervous system as well as of the hypothalamic‐pituitary‐adrenal axis (HPA) are known. However, these two systems have never been analyzed, under stimulated conditions, in parallel in the same patients. Moreover, studies using intravenous (iv) corticotropin releasing factor (CRF) to assess neuroendocrine function bypass the hypothalamic component of the HPA axis. Therefore, iv human (h) CRF (pituitary stimulation/exogenous CRF) and a multifaceted stress test (hypothalamic activation/ endogenous CRF) were compared with respect to their effects on hemodynamics as well as plasma norepinephrine (NE), epinephrine (E), ACTH, and cortisol in abstinent alcoholics (n= 11) versus healthy men (n= 10). Each stimulus was tested twice, 12 weeks apart, in two separate experimental blocks (I and II). Alcoholics entered block 18 days after the last ethanol ingestion and were controlled for abstinence up to block II. hCRF caused a fall in mean arterial pressure (MAP), most pronounced in alcoholics, particularly in block II. In contrast, stress testing raised MAP in both groups and blocks. A sustained increase in ACTH, cortisol, and NE occurred after hCRF, although the ACTH response in alcoholics was blunted in both blocks. Stress testing elevated NE in both groups and blocks, while raising plasma ACTH and cortisol during block I only in controls. However, unlike the persistently blunted ACTH response to iv CRF, a normalization of the stress‐induced ACTH output occurred in alcoholics after 12 weeks of abstinence. During block I, basal E levels were elevated in alcoholics whereas NE levels tended to be lower than in controls, resulting in a significantly decreased NE/E ratio that returned to near control values in block II. Neither CRF nor stress had any effect on circulating E in either group or block. To conclude: (1) Normalization of the ACTH response to stress, but not to iv CRF, after 12 weeks of abstinence, suggests that other ACTH secretagogues may be compensating for CRF dysfunction in alcoholics. (2) Despite the dramatically lowered plasma NE/E ratio in alcoholics, the NE response to stimuli was unaffected. (3) The exaggerated hypotensive reaction and blunted ACTH response to iv CRF may reveal a long‐term dissociative dysregulation of CRF actions in alcoholics.
Regional Restriction of Alcohol/Retinol Dehydrogenases along the Mouse Gastrointestinal Epithelium
Authors: Haselbeck Robert J. , Duester Gregg
Published: May 2006

The gastrointestinal tract is a major site of alcohol dehydrogenase (ADH) activity in humans and rodents. Because class IADH (ADH‐I) and class IV ADH (ADH‐IV), but not class III ADH (ADH‐III), function as retinol dehydrogenases in vitro and may thus participate in retinoid signaling needed for epithelial differentiation, the aim of this study was to determine the localization of these enzymes along the gastrointestinal tract. Specific antibodies were used to examine the tissue distribution of all three known classes of mouse ADH by Western blotting, and cellular localization was determined by immunohistochemistry. ADH‐I was detected primarily in the intestine, liver, kidney, adrenal, and uterus, with detection of ADH‐III in all tissues examined, and detection of ADH‐IV primarily in the esophagus, stomach, adrenal, skin, ovary, and epididymis. Along the gastrointestinal tract, ADH‐III was not specifically localized, whereas ADH‐I was localized exclusively in the villus epithelium of the small intestine and absorptive epithelium of the large intestine, with ADH‐IV being localized exclusively in the basal and suprabasal epithelial cells of the esophagus and gastric pit surface epithelium of the stomach. The ADH localization patterns observed are consistent with ADH‐I and ADH‐IV, but not ADH‐III, functioning physiologically in retinol metabolism needed for epithelial differentiation. Our results further suggest that the functions of ADH‐I and ADH‐IV are regionally restricted to the lower and upper components, respectively, of the gastrointestinal epithelium, a finding that may relate to the different efficiencies of these two enzymes for retinol oxidation, as well as to the different susceptibilities of the upper and lower digestive tracts for ethanol‐induced cancers.
Fetal Alcohol Exposure Augments the Blunting of Tumor Necrosis Factor Production In Vitro Resulting from In Vivo Priming with Lipopolysaccharide in Young Adult Male But Not Female Rats
Authors: Chiappelli Francesco , Kung Michelle A. , Tio Delia L. , Tritt Susan H. , Yirmiya Raz , Taylor Anna N.
Published: May 2006

We previously reported altered responses of thymocytes and splenocytes to mitogen stimulation in fetal alcohol‐exposed (FAE) male Sprague‐Dawley rats. We also reported enhanced neuroendocrine responses to stressful stimuli in these animals. The experiments we describe herein aimed at testing whether young adult FAE rats manifest a notable deregulation in the neuroendocrine‐immune response to pathogen administration. We tested the effect of in vivo priming of the animal with a low dose of endotoxin [lipopolysaccharide (LPS), 5 μg/kg], considered to be suboptimal from the perspective of mounting detectable levels of circulating monokines several hours after administration, upon the production of immunoreactive tumor necrosis factor (TNF‐α) in response to a further in vitro challenge of peripheral blood mononuclear cells with 2.5 μg/ml of LPS 90 min after priming. We show that the response to the LPS pathogen in vitro after priming is significantly blunted (p < 0.01) in male rats exposed prenatally to alcohol, compared with control male animals. FAE female rats and FAE ovariectomized female rats do not show significant differences in the priming response, compared with control animals. We also show that there is no correspondence between plasma corticosterone levels and TNF‐α production after priming in any of the groups tested.
Ontogeny of Hypothalamic Corticotropin‐Releasing Factor and Anterior Pituitary Pro‐opiomelanocortin Expression in Male and Female Offspring of Alcohol‐Exposed and Adrenalectomized Dams
Authors: Aird Fraser , Halasz Ildiko , Redei Eva
Published: May 2006

This study was designed to determine whether the previously described sexually dimorphic changes in rat hypothalamic corticotrop‐in‐releasing factor (CRF) and anterior pituitary pro‐opiomelanocortin (POMC) mRNA expression in response to fetal alcohol exposure (FAE) are present prepubertally and whether they are altered by maternal adrenalectomy. Hypothalamic CRF and anterior pituitary POMC mRNA levels were determined in male and female offspring of adrenalectomized (ADX) and sham‐adrenalectomized (Sham) dams exposed to alcohol (FAE) or a pair‐fed (PF) control diet during the last 2 weeks of gestation. CRF and POMC mRNA levels were measured by Northern blotting at 1, 7, 14, and 21 days of age. In offspring of control PF dams, CRF mRNA levels increased faster in females, increasing by day 7, followed by a decrease at days 14 and 21, whereas in males there was a gradual increase from days 1 to 21. FAE altered the ontogenic profile of CRF mRNA in female offspring by delaying and exaggerating the rise of CRF expression to day 14, but produced no effect in males. Maternal adrenalectomy, combined with FAE, resulted in an early rise of CRF mRNA on day 14 in male offspring. In females, the combined ADX/FAE treatment resulted in significantly increased CRF mRNA levels, compared with those of ADX/PF offspring, on days 7 and 14. By day 21, these differences in CRF mRNA levels between the ADX/FAE and ADX/PF offspring had disappeared. POMC mRNA levels generally increased by day 7, followed by a dramatic decrease by day 14 and another increase by day 21. FAE male offspring showed decreased levels of POMC mRNA, whereas females were not affected. Maternal adrenalectomy reversed this inhibition in male offspring, resulting in POMC mRNA levels similar to those measured in male offspring of PF control animals. In contrast, POMC mRNA levels of female offspring of ADX dams decreased in response to FAE. These data suggest that the previously observed switch from suppressed to enhanced POMC expression in FAE males is the result of developmental events beyond weaning. Because this sexually dimorphic regulation of CRF and POMC expression by prenatal alcohol exposure and maternal adrenalectomy occurs before the presence of adult levels of sex steroids, this suggests an organizational effect on the developing hypothalamic‐pituitary‐adrenal function.
Gender Differences in Comorbidly Depressed Alcohol‐Dependent Outpatients
Authors: Pettinati Helen M. , Pierce John D. , Wolf Alexia L. , Rukstalis Margaret R. , O'Brien Charles P.
Published: May 2006

Clinical profiles of alcohol‐dependent male and female outpatients were evaluated at treatment entry to compare the level of clinical severity in alcoholics with a coexistent comorbid depressive disorder to alcoholics who have never been depressed. Due to a higher proportion of females than males in the depressed alcoholic population, selected patient groups were oversampled to create a study group with equivalent number of males and females with and without comorbid depression. Clinical severity was assessed by examining both the extent of alcohol problems, and depressive symptomatology at treatment entry with respect to gender differences (unrelated to depression), effects of comorbid depression (unrelated to gender), and effects from the interaction of gender and depression. There were 93 DSM‐III‐R alcohol‐dependent outpatients (SO males, 43 females), half of whom had a current or lifetime DSM‐III‐R depressive disorder. The amount of drinking in the 90 days before treatment entry, the degree of alcohol severity, and the number of lifetime drinking‐related consequences were collected in the first week after detoxification. Diagnoses of lifetime and current depression were determined via the Structured Clinical Interview for DSM‐III‐R, and depressive symptoms were evaluated with rating scales 1 week after detoxification. In most cases, a depressive disorder was diagnosed only if sometime in the patient's history depressive symptoms had either predated problem drinking or been present during a 6‐month abstinent period. Results: depressed males had a more severe clinical profile with respect to their alcoholism (i.e., more drinking, drinking‐related problems, and alcohol severity than depressed females and never‐depressed males). Surprisingly, females who had never been depressed (also no family history of depression) reported drinking the same quantities of alcohol in the 90 days before treatment and had comparable alcohol severity and number of consequences as males who had never been depressed. Depressed females, however, were more severely depressed (i.e., reported more intensive depressive symptoms than depressed male alcoholics). Thus, determining the type and extent of clinical severity at treatment entry in comorbidly depressed alcoholics depends on the gender of the patient. The significant interaction between gender and the presence of comorbid depression that was found in this study may have important implications for predicting success in treatment.
Effect of Alcohol on Exercise‐Induced Changes in Serum Glucose and Serum Free Fatty Acids
Authors: Heikkonen Erkki , Ylikahri Reino , Roine Risto , Välimäki Matti , Härkönen Matti , Salaspuro Mikko
Published: May 2006

The effect of alcohol on exercise‐induced changes in serum glucose, serum free fatty acids, and serum insulin was studied in healthy male volunteers by performing an exhaustive ergometer exercise: (1) followed by alcohol intoxication (induced by 1.5 g of alcohol/kg of body weight); (2) during alcohol intoxication (induced by 0.8 g of alcohol/kg of body weight); and (3) during hangover (13 hr after a dose of 1.5 g of alcohol/kg of body weight). Acute alcohol intake immediately before exercise inhibited the exercise‐induced increase in mean serum glucose concentration and caused a mild decrease in serum glucose levels during recovery from exercise. Exercise during hangover also resulted in decreased glucose levels during recovery from exercise. Alcohol administration immediately before or after exercise inhibited the postexercise increase in mean serum free fatty acids concentration. This was not seen during hangover, when blood alcohol concentration had already reached 0. In conclusion, alcohol interferes with the metabolism of carbohydrates during and after anaerobic exercise by decreasing the availability of circulating glucose. Furthermore, during recovery from exercise, alcohol decreases the supply of free fatty acids for the body.
Clinical Characteristics and Disease Course of Alcoholics with Inactive Aldehyde Dehydrogenase‐2
Authors: Murayama Masanobu , Matsushita Sachio , Muramatsu Taro , Higuchi Susumu
Published: May 2006

Inactive aldehyde dehydrogenase‐2 (ALDH2) is known as a genetic negative risk factor for the development of alcoholism. In alcoholics with inactive ALDH2, unidentified factors that overcome the adverse reactions of high blood acetaldehyde concentration after drinking may increase such persons' susceptibility to alcoholism. Comparison of clinical characteristics, including sociofamilial backgrounds and psychopathologies, failed to show significant differences between alcoholics with inactive ALDH2 (inactive group) and those with active ALDH2 (active group). Examination of the temporal profile of disease development showed that the inactive group experienced each stage or event in the history of drinking and alcoholism 1 to 5 years later in life than the active group; however, not all comparisons reached statistically significant levels. Although preliminary, these results suggest that an inactive ALDH2‐mediated delay in the occurrence of alcohol‐related problems seems to contribute to the suppression of alcoholism development.
Self‐Reported Flushing and Genotypes of ALDH2, ADH2, and ADH3 among Taiwanese Han
Authors: Chen Wei J. , Chen Chiao‐Chicy , Yu Jeng‐Ming , Cheng Andrew T. A.
Published: May 2006

The aims of this study are to investigate whether self‐reported facial flushing postalcohol consumption (PAC) among subjects with ALDH2*1/*1 can be attributed to ADH2 or ADH3 and whether the prediction of ALDH2 genotype can be improved by examining the combination of flushing and other accompanying reactions of PAC sensitivity. Fifty‐eight subjects of Han ancestry in Taiwan were interviewed for alcohol‐sensitivity reactions and their blood samples were genotyped for ALDH2, ADH2, and ADH3. For subjects with ALDH2*1/*1 (n= 46), 70% reported to have no flushing PAC and 30% reported flushing PAC. When subjects with ALDH2*1/*1 had ADH2*1/*1 (n= 11), all reported to have no flushing; otherwise, 35% (for ADH2*1/*2, n= 17) and 44% (for ADH2*2/*2, n= 18) reported flushing. For subjects with ALDH2*1/*1 and at least one ADH2*2 allele, the genotype of ADH3 was not associated with self‐reported flushing. PAC flushers with ALDH2M/M (50%) were more likely to report nausea than those with ALDH2*1/*2 (8%). The probability of ALDH2*1/*1 given flushing reported was 0.29, while the probability of ALDH2*1/*1 given both flushing and nausea reported was 0.71. The results indicate that self‐reported flushing is determined by both ALDH2 and ADH2 and that prediction of ALDH2 genotype on the basis of self‐reported flushing and nausea can help identify subjects at increased risk for alcoholism.
Effects of Chronic Ethanol Consumption and Aging on Proenkephalin and Neurotensin
Authors: Tajuddin Nuzhath F. , Druse Mary J.
Published: May 2006

We examined the combined effects of chronic ethanol consumption and aging on mRNA and peptide for proenkephalin (PE), the precursor of met‐ and leu‐enkephalin. This study also evaluated the effects of aging and alcohol on the level of the mRNA encoding the common precursor of neurotensin (NT) and neuromedin N (NN). PE mRNA and NT/NN mRNA were quantitated in multiple brain areas of 5‐ and 24‐month‐old male Fischer 344 rats. Aging, but not chronic ethanol consumption, altered PE mRNA and peptide levels. Aging was accompanied by a loss of PE peptide and PE mRNA in the rostral striatum. In aged rats, PE mRNA was also reduced in the shell region of the nucleus accumbens. The decline in PE mRNA in the rostral striatum and shell region of the nucleus accumbens was caused by a reduction in the number of cells that contain PE mRNA. The percentage of PE mRNA‐containing neurons that express a high amount of PE mRNA was also lower in the rostral striatum of 24‐month‐old rats. The effects of aging may impair motor function and alter the rewarding properties of ethanol consumption. Neither aging nor alcohol changed the PE mRNA levels in the core region of the nucleus accumbens, the frontal cortex, and the piriform cortex. In contrast to PE mRNA, neither aging nor chronic ethanol consumption affected NT/NN mRNA in the regions analyzed. Normal NT/NN mRNA levels were found in the lateral septum and two hippocampal brain areas: the dorsal subiculum and CA1 regions.
The Alcohol Deprivation Effect in the Alcohol‐Preferring P Rat under Free‐Drinking and Operant Access Conditions
Authors: McKinzie D. L. , Nowak K. L. , Yorger L. , McBride W. J. , Murphy J. M. , Lumeng L. , Li T.‐K.
Published: May 2006

The alcohol‐deprivation effect (ADE) was examined under 4‐hr operant and 24‐hr free‐choice alcohol access in the alcohol‐preferring (P) rat after deprivation intervals from 2 to 4 weeks. Results indicated that adult male P rats responding for 6 weeks on a concurrent FR‐5/ FR‐1 schedule of reinforcement for alcohol and water, respectively, and then deprived of alcohol for 2 weeks, demonstrated a 40% increase in alcohol responding during the first 60 min of alcohol reinstatement. The alcohol deprivation effect was temporary, however, as responding did not differ from baseline levels on the second day of reinstatement. In a second experiment, weanling male and female P rats received 7 weeks of continuous access to alcohol, beginning at 21 days of age, and were then deprived of alcohol for 4 weeks. On the first day of alcohol reinstatement, P rats exhibited a 40% to 45% increase from baseline alcohol drinking levels, with alcohol intake returning to baseline levels by the 3rd day of reinstatement. Although alcohol intake was higher in females than in males when adjustment was made for body weight, there were no gender differences in the magnitude of the alcohol deprivation effect. Taken together, these results indicate that the ADE is a long‐lasting phenomenon that occurs under both operant and continuous access conditions in the P rat, and thus these rats may be useful models for the study of factors involved in relapse of alcohol drinking.
Cytotoxicity and Apoptosis Produced by Arachidonic Acid in HepG2 Cells Overexpressing Human Cytochrome P‐4502E1
Authors: Chen Qi , Galleano Monica , Cederbaum Arthur I.
Published: May 2006

The goal of the current study was to evaluate the effects of arachidonic acid, as a representative polyunsaturated fatty acid, on the viability of a HepG2 cell line, which has been transduced to express human cytochrome P4502E1 (CYP2El). Arachidonic acid produced a concentration‐ and time‐dependent toxicity to HepG2‐MV2E1‐9 cells, which express CYP2E1, but little or no toxicity was found with control cells. In contrast to arachidonic acid, oleic acid was not toxic to the HepG2‐MV2E1‐9 cells. The cytotoxicity of arachidonic acid involved a lipid peroxidation type of mechanism since toxicity was enhanced after depletion of cellular glutathione; formation of malon‐dialdehyde and 4‐hydroxy‐2‐nonenal was markedly elevated in the cells expressing CYP2E1, and toxicity was prevented by antioxidants and the iron chelator desferrioxamine. The CYP2E1‐dependent arachidonic acid toxicity appeared to involve apoptosis, as demonstrated by terminal deoxynucleotidyltransferase‐mediated dUTP nick end labeling and DNA laddering experiments. Trolox, which prevented toxicity of arachidonic acid, also prevented the apoptosis. Transfection with a plasmid containing bcl‐2 resulted in complete protection against the CYP2E1‐dependent arachidonic acid toxicity. It is proposed that elevated production of reactive oxygen intermediates by cells expressing CYP2E1 can cause lipid peroxidation, which subsequently promotes apoptosis and cell toxicity when the cells are enriched with polyunsaturated fatty acids such as arachidonic acid.
Association Study Between the 441C Ins/Del and TaqI A Polymorphisms of the Dopamine D2 Receptor Gene and Alcoholism
Authors: Ishiguro Hiroki , Arinami Tadao , Saito Toshikazu , Akazawa Shigeru , Enomoto Minoru , Mitushio Hiroshi , Fujishiro Hiroshi , Tada Kunimaro , Akimoto Yutaka , Mifune Hideo , Shioduka Shinichi , Hamaguchi Hideo , Toru Michio , Shibuya Haruo
Published: May 2006

Dopamine D2 receptors have been implicated in the biology of alcohol preference. We examined the‐141 C Ins/Del polymorphism in the promoter region of the dopamine D2 receptor gene (DRD2) and the DRD2 Taql A polymorphisms in 209 Japanese alcoholics and 152 age‐ and sex‐matched Japanese controls. The Ins allele was significantly increased in the alcoholics, compared with the controls (p < 0.002, odds ratio = 1.82). The Taql A1 allele tended to be more frequent in the alcoholics than in the controls (p < 0.04). Linkage disequilibrium between these two polymorphisms was weak (a maximum δ value = 0.13). The ‐141 C Ins/Del polymorphism may affect the vulnerability for alcoholism presumably through different expression of DRD2 in the Japanese.
Ethanol Counteraction of Clonidine‐Evoked Inhibition of Norepinephrine Release in Rostral Ventrolateral Medulla of Rats
Authors: Mao Limin , Abdel‐Rahman Abdel A.
Published: May 2006

Previous studies from our laboratory demonstrated an antagonistic hemodynamic interaction between ethanol and clonidine in conscious and in urethane‐anesthetized rats. The present study tested the hypothesis that ethanol produces its effect by counteracting clonidine‐evoked inhibition of norepinephrine (NE) release at its major site of action, the rostral ventrolateral medulla (RVLM). In vivo electrochemical measurement of real‐time changes in NE level in the RVLM of urethane‐anesthetized Sprague‐Dawley rats was made along with blood pressure and heart rate. Clonidine (30 μg/kg, iv) produced significant decreases (p < 0.05) in NE electrochemical signal and blood pressure. Ethanol (1 g/kg, iv) administered 10 min after clonidine significantly (p < 0.05) increased NE signal and counteracted clonidine‐evoked hypotension. Equal volume of saline had no effect on NE signal in the RVLM nor on the hypotensive response to clonidine. Pretreatment with the same dose of ethanol (1 g/kg) caused slight increases in RVLM NE level and in blood pressure, but did not influence the electrochemical and blood pressure responses to clonidine; clonidine (30 μg/kg) administration 10 min after ethanol resulted in significant (p < 0.05) decreases in NE signal and blood pressure. These findings suggest that: (i) ethanol counteraction of the hypotensive action of clonidine involves, at least in part, opposite effects on central pathways that use NE as a neurotransmitter; (ii) the RVLM represents a possible site for the adverse hemodynamic interaction between ethanol and clonidine; and (iii) ethanol‐evoked increase in RVLM NE, which correlates with its pressor effect, is much enhanced when RVLM NE level is reduced by clonidine.