Ethanol-Reinforced Responding by AA and ANA Rats Following the Sucrose-Substitution Initiation Procedure

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.     

Maternal separation alters acquisition of ethanol intake in male ethanol-preferring AA rats

BACKGROUND: Prolonged daily maternal separation can increase the risk for developing substance abuse, whereas brief maternal separation has been reported to induce positive behavioral effects, decrease voluntary ethanol intake and induce long-lasting changes in brain opioid peptides. The ethanol-preferring AA (Alko, Alcohol) rats have altered basal levels of endogenous opioid peptides that may relate to their high voluntary ethanol intake. The purpose of this study was to investigate whether maternal separation could affect acquisition of ethanol intake in AA rats. METHODS: The rat pups were exposed to 15 min (MS15) or 360 min (MS360) of maternal separation during postnatal day 1-21, while control rats were exposed to normal animal facility rearing. As adults, the male rats were gradually introduced to increasing concentrations of ethanol. Furthermore, the effect of restraint stress on voluntary ethanol intake was investigated. RESULTS: The MS15 rats reached a high voluntary ethanol intake later than MS360 and control rats. The MS15 rats had a lower ethanol intake and preference at 8% ethanol compared to MS360 rats and lower ethanol intake compared to control rats. MS15 rats also had a lower 10% ethanol intake in comparison with MS360 rats. Restraint stress decreased the ethanol intake in MS15 and MS360 rats, whereas the ethanol intake in control rats was unaffected. CONCLUSIONS: We have previously shown that prolonged periods of maternal separation in Wistar rats result in an increased ethanol intake later in life. This was not repeated in this study, using AA rats with an inherent high ethanol intake. However, it is shown that brief maternal separation can delay acquisition of high ethanol intake and in addition decrease voluntary ethanol intake and preference in AA rats. Maternal separation for 15 min is therefore suggested to protect against high voluntary ethanol intake later in life.     

Impact of acute and chronic ethanol exposure on prolactin in both male and female rats

The deleterious effects of ethanol (EtOH) on reproduction have been well documented. This disruption is usually associated with alterations in prolactin (PRL) levels, which is relevant since this hormone is an important participant in the reproductive system. Reported EtOH-induced changes in PRL (i.e., stimulation or inhibition) have varied. These differences may have been owing to the gender or age/sexual maturity of the animal and the mode of the administration of EtOH. Therefore, to clarify the impact of EtOH on PRL, a series of experiments were conducted utilizing rats of both genders, exposed to EtOH acutely or chronically, as adults and as they progressed through puberty. In general, in younger animals of both genders, EtOH depressed serum PRL whether given acutely or chronically. In adult males, acute EtOH actually stimulated PRL levels while chronic administration had no effect. In adult females, EtOH’s effect was highly dependent on the stage of the estrous cycle in which EtOH was given and during which PRL was measured. In conclusion, our studies have shown that the PRL response to EtOH is dependent on the gender and age/sexual maturity of the animals as well as on the mode of administration.     

Effects of ethanol exposure on subsequent acquisition and extinction of ethanol self-administration and expression of alcohol-seeking behavior in adult alcohol-preferring (P) rats: I. Periadolescent exposure

Background The current study examined the effects of ethanol (EtOH) drinking during periadolescence on the subsequent acquisition and extinction of operant self‐administration of EtOH and expression of alcohol‐seeking behavior in adult alcohol‐preferring (P) rats to test the hypothesis that alcohol drinking during periadolescence produces enduring alterations that enhance the reinforcing properties of EtOH. Methods Periadolescent female P rats were given 24 hr free‐choice access to 15% (v/v) EtOH starting at postnatal day (PND) 30 and ending on PND 60 or were similarly housed and received water only. On PND 75, without any prior training, periadolescent alcohol‐drinking and periadolescent alcohol‐naïve rats were placed in standard two‐lever (15% EtOH and water) chambers to examine acquisition of EtOH self‐administration with a fixed ratio (FR) 1 schedule of reinforcement. After the acquisition phase and after stable responding was established on an FR5 for EtOH and FR1 for water, P rats underwent extinction training for both EtOH and water rewards. After extinction training and a 2 week home cage period, rats were returned to the operant chambers in the absence of reward for seven consecutive sessions (Pavlovian spontaneous recovery). After this testing period, animals were maintained in their home cage for a week before being returned to the operant chambers and allowed to respond for EtOH and water (reacquisition). Results Compared with periadolescent alcohol‐naïve rats, periadolescent alcohol‐drinking rats acquired EtOH responding sooner (i.e., in the first acquisition session), displayed a greater resistance to extinguish EtOH responding (i.e., higher levels of responding in sessions 4–6), had higher responding for more sessions on the EtOH lever in the absence of reward after a prolonged home cage rest period, and had a more prolonged elevated level of EtOH responding during reacquisition (four sessions versus one session). Conclusions Overall, the results suggest that periadolescent EtOH drinking by P rats produced long‐lasting alterations in the reinforcing effects of alcohol, which increased the likelihood that alcohol drinking would be initiated in adulthood, decreased the likelihood that once adult alcohol drinking began it could be extinguished easily, and increased the potential for relapse.     

Effects of Lifelong Ethanol Consumption on Cerebellar Layer Volumes in AA and ANA Rats

Aging and chronic alcohol consumption can cause degenerative changes in the cerebellar cortex. In this study, the effects of aging and lifelong alcohol consumption on cerebellar cortical layer volumes (molecular and granular) and also white matter layer volumes were studied in alcohol-preferring (AA) and nonpreferring (ANA) rats of both sexes. The ethanol-consuming animals (EtOH) had 12% (w/v) ethanol as the only available fluid from 4 to 22 months of age, whereas the young (3 month) and old controls (24 months) had only water to drink. The volumes of molecular, granular, and white matter layers of the cerebellar vermis in folia II, IV, VII, and X were measured by using systematic sampling and a point-counting method. The volumes of the granular and white matter layers showed consistent increase between 3 and 24 months of age, whereas the volume of the molecular layer remained unchanged with increasing age. Individual ethanol intake was measured over a 1-week period at the beginning and at the end of chronic ethanol exposure. Significant (ANOVA, P= 0.000) sex difference was found in the drinking behavior in both lines, with females consuming more alcohol than males (daily ethanol consumption at 22 months of age 3.2 ± 0.3 vs. 7.1 ± 0.3 g/kg for AA males and females; 3.2 ± 0.3 vs. 5.4 ± 0.4 g/kg for ANA males and females, respectively). The only ethanol-induced effect on the cerebellum was observed in ANA-EtOH females with a 15% reduction in the volumes of the molecular and granular layer in folium II compared with age-matched controls and a significant (P < 0.05, analysis of covariance with ethanol intake as a covariate) line difference in folium II (molecular and granular layers) was observed between ANA-EtOH females and AA-EtOH females. Furthermore, the volume of the molecular layer in folium II was significantly (P < 0.05, analysis of covariance with ethanol intake and body weights as covariates) reduced for ANA-EtOH females, compared with ANA-EtOH males indicating a sex difference in the cerebellar degeneration due to chronic alcohol consumption. Of the three layers studied, the white matter layer was the most resistant layer to the effects caused by chronic alcohol consumption. In view of the fact that AA and ANA rats of both sexes differ regarding the drinking behavior and ethanol metabolism, they provide an important model for further research on ethanol-induced pathological changes in the central nervous system.     

The effects of continuous and intermittent ethanol exposure in adolesence on the aversive properties of ethanol during adulthood

Background:  Alcohol abuse among adolescents is prevalent. Epidemiological studies suggest that alcohol abuse during the adolescent developmental period may result in long-term changes such as an increased susceptibility to alcohol-related problems in adulthood. Laboratory findings suggest that alcohol exposure during the adolescent developmental period, as compared with adulthood, may differentially impact subsequent neurobehavioral responses to alcohol. The present study was designed to examine whether ethanol exposure, continuous versus intermittent, during the adolescent developmental period would alter the aversive properties of ethanol in adult C3H mice.
Methods:  Periadolescent (PD28) male C3H mice were exposed to 64 hours of continuous or intermittent ethanol vapor. As a comparison, adult (PD70) C3H mice were also exposed to 64 hours of continuous or intermittent ethanol vapor. Six weeks after ethanol exposure, taste aversion conditioning was carried out on both ethanol pre-exposed and ethanol-naive animals using a 1-trial, 1-flavor taste-conditioning procedure.
Results:  Ethanol exposure during the periadolescent period significantly attenuated a subsequent ethanol-induced conditioned taste aversion, as compared with control animals. Adult animals exposed to chronic ethanol vapor during adolescence showed less of an aversion to an ethanol-paired flavor than ethanol-naive adults. Intermittent exposure to ethanol vapor during periadolescence produced a greater attenuation.
Conclusion:  It is suggested that ethanol exposure during the periadolescent period results in long-term neurobehavioral changes, which lessen a conditioned aversion to ethanol in adulthood. It is suggested that this age-related effect may underlie the increased susceptibility to alcohol-related problems which is negatively correlated with the age of onset for alcohol abuse.     

Short and prolonged periods of maternal separation and voluntary ethanol intake in male and female ethanol-preferring AA and ethanol-avoiding ANA rats

BACKGROUND: Genetic as well as environmental factors can affect the propensity for psychopathology and/or drug dependence. Maternal separation represents an animal experimental model that is useful in studies of effects of early life experiences. The authors have established a protocol for short and prolonged periods of maternal separation to study adult neurochemistry, behavior, and ethanol intake and have previously reported alterations in ethanol intake in Wistar rats and ethanol-preferring rats. The aim of the current study was to more thoroughly study how early life experiences affect an inherited propensity for high and low ethanol intake, respectively, in male and female ethanol-preferring AA (Alko alcohol) and ethanol-avoiding ANA (Alko, Non-Alcohol) rats. METHODS: AA and ANA pups were assigned to one of three different rearing conditions: 15 min (MS15) or 360 min (MS360) of daily maternal separation in litters or normal animal facility rearing (AFR) during postnatal days 1 to 21. In adulthood, voluntary ethanol intake was investigated using the two-bottle free choice paradigm. RESULTS: In male ethanol-preferring AA rats, MS15 resulted in a lower intake and fewer high-preferring animals at 8% and 10% ethanol compared with MS360 rats. The male MS360 rats had a higher ethanol intake at 8% and 10% ethanol in comparison with AFR rats. In contrast, the female AA MS15 and MS360 rats had a lower ethanol intake and a lower preference for the 10% ethanol solution compared with the female AA AFR rats. In male and female ANA rats, no major separation-induced effects were found. CONCLUSIONS: The current results show that genetic inheritance can be affected by environmental manipulations in AA rats with an inherent high ethanol intake. The findings in female ethanol-preferring AA rats give further evidence of a differential outcome of maternal separation in male and female rats, as previously shown.     

Fetal and maternal sheep hypothalamus pituitary adrenal axis responses to chronic binge ethanol exposure during the third trimester equivalent

BACKGROUND: We tested the hypothesis that in utero ethanol exposure results in changes in fetal and maternal adrenocorticotropin (ACTH) and cortisol during the third trimester equivalent, by using a chronically instrumented fetal sheep model. METHODS: Pregnant ewes received saline or ethanol intravenously 3 consecutive days per week from day 109 to day 132 of gestation. Fetal and maternal blood samples were collected on days 118 and 132. RESULTS: Maternal and fetal ACTH and cortisol values increased on days 118 and 132 of gestation in response to ethanol infusions that created blood ethanol concentrations (BECs) that are easily achievable by human drinkers. Peak ACTH and cortisol values were detected 30 to 60 min after peak BECs were achieved. CONCLUSIONS: Chronic ethanol exposure during the third trimester equivalent in sheep resulted in repeated activation of the hypothalamus-pituitary-adrenal axis in both the mother and fetus. Temporally, the patterns of maternal and fetal responses to ethanol infusion were similar. We conclude that ovine maternal ethanol exposure during the third trimester equivalent increases fetal ACTH and cortisol concentrations, hormonal responses that may play a role in mediating alcohol-related birth defects.     

Alterations in circadian rhythm phase shifting ability in rats following ethanol exposure during the third trimester brain growth spurt

BACKGROUND: Disruptions in sleep and feeding rhythms are among the consequences of prenatal alcohol exposure. Previously, we reported that ethanol exposure during the second trimester equivalent in rats produces long-lasting impairments in circadian system functioning. In the present study, we examined the effects of ethanol exposure during the third trimester equivalent brain growth spurt on the development of the circadian clock system. METHODS: Sprague-Dawley male rat pups were exposed to 6.0 g/kg/d ethanol via an artificial rearing procedure on postnatal days (PD) 4 through 9 (EtOH). An artificially reared gastrostomized control group and a normally reared suckle control group were also included. At 10 to 12 weeks of age, wheel-running behavior was measured continuously under a 12-hour/12-hour light/dark (LD) cycle. Thereafter, subjects were exposed to a 6-hour phase delay of the LD cycle, and the ability to adjust to the new LD cycle was evaluated. RESULTS: Before the phase delay, onset time of activity and acrophases of activity in all 3 groups were not significantly different from one another. After the 6-hour LD cycle delay, EtOH subjects were slower to adapt to the new cycle compared with both control groups, as measured by both activity onset and acrophase. Throughout the experiment, activity levels of EtOH subjects tended to be higher compared to both controls. CONCLUSIONS: These data demonstrate that ethanol exposure during the third trimester disrupts the ability to synchronize circadian rhythm to light cues. Disruptions in circadian regulation may cause abnormal behavioral rhythmicity, such as disrupted sleep and feeding patterns, as seen in individuals prenatally exposed to ethanol.     

Effects of ethanol exposure on subsequent acquisition and extinction of ethanol self-administration and expression of alcohol-seeking behavior in adult alcohol-preferring (P) rats: II. Adult exposure

Background In a preceding study, we reported that ethanol (EtOH) consumption during periadolescence in alcohol‐preferring (P) rats produced significant effects on the acquisition, extinction, Pavlovian spontaneous recovery (PSR), and reacquisition of operant self‐administration of EtOH. The objective of the present study was to determine if EtOH consumption during adulthood produced similar effects on subsequent operant behaviors. Methods Adult female P rats (>135 days of age) were given 24 hr free‐choice access to 15% EtOH for 30 days or were similarly housed and received water only. After a 15 day period of no EtOH access and without any prior training, adult alcohol drinking and adult alcohol‐naïve rats were placed in standard two‐lever (15% EtOH and water) chambers to examine acquisition of EtOH self‐administration. After stable responding was established on a concurrent fixed ratio (FR) 5 FR1 schedule for EtOH versus water, the P rats underwent extinction training for nine sessions. After extinction and a 2 week home cage period (with no operant sessions or access to EtOH), rats were returned to the operant chambers in the absence of reward for seven consecutive sessions to test for PSR. After PSR testing, animals were maintained in their home cage for a week, before being reintroduced to the operant chambers and allowed to respond for EtOH and water. Results Both the adult alcohol‐drinking and adult alcohol‐naïve groups rapidly acquired EtOH self‐administration, expressed a pronounced PSR, which was augmented by EtOH priming and the presence of a discriminative stimulus (odor cue), and increased responding when EtOH was reinstated. Adult pre‐exposure to EtOH did not alter any of the operant measures. Conclusions The results of this study suggest that, unlike the results with EtOH pre‐exposure during periadolescence, chronic alcohol drinking by P rats in adulthood did not produce sufficient long‐lasting changes in neuronal function to alter subsequent operant acquisition of alcohol self‐administration, alcohol relapse, or alcohol‐seeking behavior.     

The decreased cellular expression of neuropeptide Y protein in rat brain structures during ethanol withdrawal after chronic ethanol exposure

Background: Neuropeptide Y (NPY) has been implicated in the alcohol-drinking behaviors of rodents. This study investigated the possible involvement of NPY in the neuroadaptational mechanisms to chronic ethanol exposure and its withdrawal.
Methods: Male Sprague-Dawley rats were treated either with Lieber-DeCarli ethanol diet or control diet for 15 days, and ethanol-fed rats were withdrawn for 0 and 24 hr. The protein expression of NPY was determined in cortical, hippocampal, amygdaloid, striatal, and hypothalamic structures by using the gold-immunolabeling histochemical procedure.
Results: It was found that ethanol withdrawal, but not ethanol treatment, produced significant reductions in NPY protein levels in (1) layers IV and V of the frontal and parietal cortex, (2) layer II of the piriform cortex, (3) the central and medial nuclei of the amygdala, and (4) the paraventricular nucleus of the hypothalamus in rat brain. Chronic ethanol exposure and its withdrawal had no effect on the NPY protein levels in layers II, III, and VI of the frontal and parietal cortex or cingulate gyrus, in hippocampal (CA1, CA2, CA3, and dentate gyrus) and striatal (caudate putamen and globus pallidus) structures, or in the ventro-medial hypothalamus and basolateral amygdala. However, chronic ethanol exposure and its withdrawal produced significant reductions in NPY protein levels in the arcuate nucleus of the hypothalamus and in layers IV and V of the cingulate gyrus.
Conclusions: These results suggest that the decreased protein levels of NPY in the central and medial nuclei of the amygdala, as well as in the cortical and hypothalamic structures, during ethanol withdrawal may play an important role in the neuromechanisms of some ethanol withdrawal symptoms.     

Difluoromethylornithine decreases long-lasting protein oxidation induced by neonatal ethanol exposure in the hippocampus of adolescent rats

BACKGROUND: Ethanol exposure and withdrawal during central nervous system development can cause oxidative stress and produce severe and long-lasting behavioral and morphological alterations in which polyamines seem to play an important role. However, it is not known if early ethanol exposure causes long-lasting protein oxidative damage and if polyamines play a role in such a deleterious effect of ethanol. METHODS: In this study we investigated the effects of early ethanol exposure (6 g/kg/d, by gavage), from postnatal day (PND) 1 to 8, and of the administration of difluoromethylornithine (DFMO, 500 mg/kg, i.p., on PND 8), a polyamine biosynthesis inhibitor, on the extent of oxidative modification of proteins. Indices of oxidative modification of proteins included protein carbonyls, 3-nitrotyrosine (3-NT), and protein bound 4-hydroxynonenal (HNE) in the hippocampus, cerebellum, hypothalamus, striatum, and cerebral cortex of Sprague-Dawley rats at PND 40. RESULTS: Both ethanol and DFMO administration alone increased protein carbonyl immunoreactivity in the hippocampus at PND 40, but the combination of DFMO and ethanol resulted in no effect on protein carbonyl levels. No alterations in the content of protein-bound HNE, 3-NT, or carbonyl were found in any other cerebral structure. CONCLUSIONS: These results suggest that the hippocampus is selectively affected by early ethanol exposure and by polyamine synthesis inhibition. In addition, the results suggest a role for polyamines in the long-lasting increase of protein carbonyls induced by ethanol exposure and withdrawal.     

Fetal and maternal thyroid hormone responses to ethanol exposure during the third trimester equivalent of gestation in sheep

BACKGROUND: Abnormal thyroid hormone system function in the mother or fetus during pregnancy can result in brain defects, some of which resemble those found in children with fetal alcohol syndrome. It has been hypothesized that ethanol may act to mediate alcohol-related birth defects in part by altering thyroid hormone system function. We investigated whether a binge pattern of maternal ethanol consumption over the last trimester equivalent of gestation in sheep results in an alteration in fetal or maternal thyroid function. METHODS: Pregnant ewes received saline or ethanol beginning on day 109 of gestation (term, 145 days) for three consecutive days per week followed by 4 days without exposure. The fetuses were surgically instrumented on day 113, and experiments were performed on days 118 or 132. Fetal and maternal blood samples were collected, and plasma tri-iodothyronine (T3), thyroxine (T4), and free T4 concentrations were measured. RESULTS: Fetal T3 and T4 on day 118, fetal T3 on day 132, and maternal T3 on day 132 were lower in response to ethanol. Fetal and maternal free T4 and maternal T4 did not change in response to ethanol. Fetal thymus and adrenal weights were reduced in response to ethanol. CONCLUSIONS: We conclude that, in sheep, maternal ethanol exposure during the third trimester equivalent resulting in blood ethanol concentrations that are commonly achieved by ethanol abusers decreases circulating thyroid hormone concentrations in the mother and fetus and fetal thyroid and thymus mass.     

Long-term ethanol exposure alters the sialylation index of plasma apolipoprotein J (Apo J) in rats

We have previously shown that chronic ethanol treatment impairs the glycosylation of proteins in the rat liver. Changes in the microheterogeneity of transferrin, a N-sialoprotein under chronic alcohol consumption are well established. Apolipoprotein J, another N-glycoprotein, is a normal component of plasma high-density lipoproteins in the rat and human. Apo J is also highly sialylated and, thus, may be vulnerable to the deleterious actions of ethanol. Therefore, to understand the specific nature of alterations of Apo J sialylation as a consequence of chronic ethanol treatment, we have determined: (1) the sialylation index of Apo J (moles sialic acid per mole Apo J protein) in rats administered ethanol for 4, 6, and 8 weeks and a gradual withdrawal and a follow-up abstinence for 1, 2, and 4 weeks; and (2) enzymatic activities of hepatic sialyltransferase and plasma sialidase during the same periods of alcohol treatment and abstinence in rats. Although no significant differences in the Apo J sialylation index between rats of the control and ethanol groups were found at the 4th week of alcohol treatment, a highly significant loss of 24% (p < 0.001) and 44% (p < 0.001) was found after 6 and 8 weeks, respectively, of alcohol feeding of these animals. Furthermore, a significant recovery of 38% (p < 0.001), 78% (p < 0.001), 84% (p < 0.001) and 96% (p < 0.001) in the sialylation index of Apo J were found, respectively, during withdrawal and 1, 2, and 4 weeks of subsequent alcohol abstinence in these animals. These changes in the sialic acid content of Apo J were accompanied by a similar pattern of changes in the enzyme activities of hepatic sialyltransferase and plasma sialidase in animals undergoing chronic ethanol treatment, withdrawal, and abstinence periods. The analysis of the sialylation index of Apo J seems to be a simple and feasible method to use to evaluate the extent of ethanol exposure.     

非酒精性脂肪性肝病大鼠内生性乙醇和肝组织乙醇代谢相关酶的变化*

目的 观察高脂饮食和高果糖饮食对大鼠肝脏病理、内生性乙醇、乙醇代谢酶的影响。方法 将SD大鼠18只随机分为正常组（n=6）,予以普通饲料喂养,高果糖组（n=6）接受普通饲料和含20%果糖水喂养,高脂组（n=6）接受高脂饲料喂养。造模16 w后,取肝组织进行非酒精性脂肪性肝病活动性评分（NAS）;采用Biovison试剂盒检测门静脉血乙醇水平;采用实时荧光定量PCR法检测大鼠肝组织乙醇脱氢酶（ADH1）和乙醛脱氢酶（ALDH2）mRNA水平;采用Western blot法测定肝组织ADH1和ALDH2蛋白表达水平;使用乙醇脱氢酶活性试剂盒测定肝组织匀浆乙醇脱氢酶活性。结果 在16 w末,高果糖组大鼠肝组织表现为脂肪变性,高脂组大鼠肝组织主要表现为NASH;高脂组大鼠NAS评分为5.40±0.32,显著高于对照组【（1.10±0.25）,P<0.05】和高果糖组【（2.94±0.40）,P<0.05】 ;高脂组大鼠血清内生性乙醇水平【（1.30±0.15）nmol/μL】显著高于正常组【（1.00±0.10）nmol/μL,P<0.05）】和高果糖组【（1.04±0.23）nmol/μL,P<0.05）】;高脂组大鼠ADH1 mRNA水平显著高于正常组（（1.30倍,P<0.05）和高果糖组（1.36倍,P<0.05）;高脂组大鼠ALDH2mRNA水平显著高于正常组（1.55倍,P<0.05）和高果糖组（1.44倍,P<0.05）;高脂组大鼠ADH1蛋白表达显著高于正常组（2.56倍,P<0.05）和高果糖组（2.52倍,P<0.05）;高脂组大鼠ALDH2蛋白表达显著高于正常组（1.41倍,P<0.05）和高果糖组（1.57倍,P<0.05）;高脂组大鼠肝脏乙醇脱氢酶活性为（175±28）μ/L,显著高于正常组【（72±13）μ/L,P<0.05）】和高果糖组【( 78±9)μ/L,P<0.05）】。结论 高脂饮食造模大鼠内生性乙醇浓度显著升高,乙醇脱氢酶和乙醛脱氢酶蛋白水平升高,乙醇脱氢酶活性显著升高。     

An ultrastructural study of the colocalization of biglycan and decorin with AA amyloid fibrils in human renal glomeruli

An investigation was undertaken on paraformaldehyde-fixed, Lowicryl resin-embedded renal biopsies from patients with AA amyloidosis to study the association of two small chondroitin sulphate/dermatan sulphate proteoglycans, decorin and biglycan, with amyloid fibrils using an ultrastructural immunogold technique. Biglycan was present in glomerular endothelial cells in both normal kidney and in amyloidosis, but little biglycan or decorin was present in the normal mesangial matrix. By contrast, conspicuous amounts of both biglycan and decorin were seen to be associated with amyloid fibrils in the glomerular matrix in cases of renal AA amyloidosis. The results further emphasise the close association between amyloid and extracellular matrix components which are now considered to be an integral part of the amyloid fibrils.     

GABA(A) receptor modulation during adolescence alters adult ethanol intake and preference in rats

Background: To address the hypothesis that GABA_A receptor modulation during adolescence may alter the abuse liability of ethanol during adulthood, the effects of adolescent administration of both a positive and negative GABA_A receptor modulator on adult alcohol intake and preference were assessed. Methods: Three groups of adolescent male rats received 12 injections of lorazepam (3.2 mg/kg), dehydroepiandrosterone (DHEA, 56 mg/kg), or vehicle on alternate days starting on postnatal day (PD) 35. After this time, the doses were increased to 5.6 and 100 mg/kg, respectively, for 3 more injections on alternate days. Subjects had access to 25 to 30 g of food daily, during the period of the first 6 injections, and 18 to 20 g thereafter. Food intake of each group was measured 60 minutes after food presentation, which occurred immediately after drug administration on injection days or at the same time of day on noninjection days. When subjects reached adulthood (PD 88), ethanol preference was determined on 2 separate occasions, an initial 3‐day period and a 12‐day period, in which increasing concentrations of ethanol were presented. During each preference test, intake of water, saccharin, and an ethanol/saccharin solution was measured after each 23‐hour access period. Results: During adolescence, lorazepam increased 60‐minute food intake, and this effect was enhanced under the more restrictive feeding schedule. DHEA had the opposite effect on injection days, decreasing food intake compared with noninjection days. In adulthood, the lorazepam‐treated group preferred the 2 lowest concentrations of ethanol/saccharin more than saccharin alone compared with vehicle‐treated subjects, which showed no preference for any concentration of ethanol/saccharin over saccharin. DHEA‐treated subjects showed no preference among the 3 solutions. Conclusions: These data demonstrate that GABA_A receptor modulation during adolescence can alter intake and preference for ethanol in adulthood and highlights the importance of drug history as an important variable in the liability for alcohol abuse.     

Effects of daily,light and moderate-heavy ethanol exposure on extent of hepatic injury and recovery following toxin-induced acute hepatitis in rats

Daily, light ethanol consumption enhances hepatic regeneration following 70% partial hepatectomy in rats. Whether such consumption has a beneficial effect on the outcome following toxin-induced acute hepatitis has yet to be determined. One hundred ten adult male Spragne-Dawlay rats (200–250 g) were randomized to receive daily gavages with ethanol 1.0 g/kg (light ethanol group), 3.0 g/kg (moderate–heavy ethanol group), or an equal volume of tap water (controls). On day 30, a single injection of D-galactosamine hydrochloride (1.0 g/kg) (D-gal), a potent hepatotoxin that induces liver failure within 24–48 hr, was administered intraperitoneally. Gavages were discontinued and rats killed (N = 4–6/group) on days 1, 3, 5, 7, and 10 after D-gal. Serum AST, bilirubin, and liver histology served to document the extent of liver injury and [³H] thymidine incorporation into hepatic DNA: hepatic regenerative activity. Compared to controls, peak serum AST levels were significantly decreased in the light (–40%, P < 0.05) and increased in the moderate–heavy (+32%, P < 0.05) ethanol groups. Serum bilirubin levels approximately doubled in the light ethanol group while increasing sixfold in the moderate–heavy and control groups (P < 0.05). Histologic evidence of hepatic injury (graded 0–IV) was limited in the light ethanol group, intermediate in controls, and most extensive in the moderate–heavy ethanol group (P < 0.05). Despite less hepatic injury, hepatic regeneration was similar in the light ethanol group compared to controls and significantly impaired in the moderate–heavy ethanol group (P < 0.01). In conclusion, the results of this study indicate that daily, light ethanol administration attenuates hepatic injury, improves hepatic function, and enhances hepatic regeneration following toxin-induced hepatitis in rats.