Ethanol intakes and preferences in the desalivate rat

Desalivate and control rats were tested for ethanol versus water preference (5%, 10% and 20% (v/v) ethanol solutions). Each concentration of ethanol was presented for six days in an ascending, descending, or mixed presentation schedule. Following preference tests, intakes of first 10% (15 days), then 5% (15 days), and finally 10% (5 days) ethanol as the only available fluid were determined. Blood ethanol concentrations were measured (22:00 hr, 24:00 hr, 02:00 hr) during the final 10% ethanol intake test. Desalivate and control rats showed similar aversions to ethanol at all concentrations with relative ethanol intake being a negative function of concentration. During ethanol and water intake tests, desalivates drank significantly greater amounts (ml/100 g body weight) of all drinking fluids than controls. However, for both groups intake of 10% ethanol was reduced significantly from water baseline levels. Although desalivates consumed as much ethanol as controls, their blood ethanol concentrations at all times tested were slightly lower than controls. During the ethanol intake test desalivate rats lost body weight, while control rats gained body weight.     

Effects of route of administration of ethanol on high-speed reaction time in young and old rats

The blood ethanol concentrations (BECs) and reactive capacity of young (8 months) and old (24 months) male Fischer 344 rats were compared at 5, 10, 20, 45, 65, and 90 min following the administration of ethanol (EtOH). The time-dependent effects of intragastric intubation (IG; 3 g/kg) and intraperitoneal injection (IP; 1.5 g/kg) of EtOH (20% w/v) were determined. Subsequent to IG delivery, BECs rose most rapidly within the first 20 min, but did not reach peak levels until 90 min for both young (240 mg/dl) and old rats (250 mg/dl). Following IP injections, BECs escalated within 5 min to 250 mg/dl in the young, to 175 mg/dl in the old, and declined gradually to a stabilized value of 150 mg/dl (young) and 130 mg/dl (old). The old rats never achieved the high BECs seen in the young. Reactive capacity, a measure of auditory/visual reaction time, was inversely related to BECs. As BECs (IP) declined, performance improved at a similar rate in both age groups, although the old rats' performance was more impaired than that of the young. However, BEC per se was not an adequate predictor of reactive capacity. When EtOH was delivered by IG so that BECs remained high for long periods of time, reactive capacity was far less impaired compared with IP delivery in which comparable BECs were present for only a few minutes. The possibility was noted that behavioral tolerance may have developed during the 90-min post-EtOH period, and that the IP delivery method may disrupt behavior in ways independent of brain ethanol levels.     

Effects of thiamine deficiency on food intake and body weight increment in adult female and growing rats

The present study compared the effects of thiamine (vitamin B1) deficiency (TD) on the patterns of food intake and body weight in adult female and neonatal Wistar rats. The adults weighed 250-270 g at the start and were fed for 60 days either with a synthetic TD diet (211 B1) or with the same synthetic diet+thiamine (210 B1). TD led to a marked reduction in food intake and the body weight set point, both recovering rapidly to their initial level in only 3 days after dietetic reversion. The effects of TD in developing rats were evaluated by subjecting pregnant rats to thiamine restriction during different time windows: prenatal (3 days before mating to parturition); perinatal (7 days after mating to the 10th postnatal day); and postnatal (from parturition to weaning). The effect of TD on the occurrence of low birth weight and ponderal growth retardation was examined from postnatal days 1 to 45. Only perinatal TD significantly decreased birth weight relative to untreated or pair-fed controls. Moreover, compared with the control treatments, ponderal growth retardation was not induced by prenatal TD, whereas induction of TD from perinatal into postnatal periods did cause ponderal growth retardation, with long-lasting effects persisting in adulthood. The results suggest a major physiological role of thiamine in the homeostasis of body weight programming, increment, and set point regulation in both offspring and adult female rats.     

Changes in brain lipid composition in thiamine deficient rats

Brain lipid composition was studied in thiamine deficient rats treated with thiamine antimetabolites (oxythiamine: OT, and pyrithiamine: PT) and thiamine deficient diet (TDD). After intraperitoneal injection of OT (40 mg/kg/day) or TDD feeding for 6 days, body weight gain decreased. However, the PT (500 micrograms/kg/day) treated rats or the pair fed control (PFC: TDD + thiamine of 5 mg/kg, i.p.) showed no decrease in body weight gain compared with the regular diet control (C). Brain lipid levels (total lipid, total cholesterol, triglyceride, phospholipid, sphingomyelin and cerebroside) were examined in four brain regions (cerebral cortex, subcortical structure, brain stem and cerebellum). Total lipid level increased in four regions in OT or TDD treated rats, but total lipid level in the cerebellum in PT treated rats decreased. Total cholesterol level increased in all treated rats, while the triglyceride level in the brain stem decreased dramatically in OT or TDD treated rats. Cerebroside levels of four regions in the PT, OT or TDD group remarkably decreased, and PFC rats showed a significant improvement of the decrease in cerebroside level. It is conceivable that these changes in brain lipid composition provided some clues for the histological and morphological changes of the brain as manifested by the myelin degradation in acute thiamine deficiency.     

Antioxidant effect of thiamine on acutely alcoholized rats and lack of efficacy using thiamine or glucose to reduce blood alcohol content

Although there is no consensus about the use of glucose and thiamine for the treatment of acute ethanol intoxication, this is a routine practice in many countries. Our objective was to determine the efficacy of this treatment and the changes it causes in the antioxidant status of the liver. Male Wistar rats were intoxicated with an ethanol dose of 5 g/kg and divided into three groups: ethanol (EtOH; untreated), EtOH+G (treated with glucose), and EtOH+B1 (treated with thiamine). Blood and urinary ethanol as well as hepatic malondialdehyde, reduced glutathione and vitamin E were determined in all animals. Blood alcohol levels did not differ between groups, although urinary excretion was about four times higher in the group treated with thiamine (EtOH+B1). The malondialdehyde, reduced glutathione and vitamin E values used here as parameters of the antioxidant system of the liver showed improvement for the thiamine-treated group (EtOH+B1). Treatment with glucose or thiamine was ineffective in reducing blood alcohol levels in rats with acute ethanol intoxication. However, the beneficial effect of thiamine as an antioxidant for ethanol metabolism was demonstrated. Further investigations are necessary to clarify the urinary excretion of ethanol reported here for the first time and the possibility of using thiamine as an antioxidant in situations of chronic alcohol use.     

Effect of an acute dose of ethanol on lipid peroxidation in rats: action of vitamin E.

Free radical generation is an important step in the pathogenesis of ethanol-associated liver injury. Administration of ethanol induces an increase in lipid peroxidation both by enhancing the production of oxygen reactive species and by decreasing the levels of endogenous antioxidants. This work focuses on the generation of free radicals provoked by an acute ethanol dose in rats, and the role of different dietary levels of vitamin E. The objective of this investigation was to study the effect of three different dietary levels of vitamin E (deficient, control and supplemented with 20 times higher levels) on plasma and liver lipid peroxidation (assayed by TBARS), vitamin E in plasma and liver, and hepatic glutathione concentration, in rats receiving the different diets. The animals were submitted to an acute dose of ethanol (5 g/kg body weight) administered by gavage at the end of an experimental 4 week period and were sacrificed at 0, 2, 4, 8 and 24 h after ethanol administration. Dietary vitamin E caused a dose-dependent increase in liver and plasma concentration of the vitamin, but ethanol administration decreased hepatic vitamin E in all groups. TBARS concentrations were higher in liver of rats that received the deficient diet, independent of ethanol, however, liver TBARS concentrations were low in control and supplemented groups, but increased with ethanol ingestion. Glutathione levels were lowered by ethanol administration in all groups, in different times, but recovered to this original level in 24 h time. In conclusion, vitamin E deficiency alone induces liver lipid peroxidation in rats, acute administration of ethanol affect vitamin E and GSH level and maintenance of adequate or higher vitamin E levels acts as a protective factor against free radical generation.     

Lipid peroxidation in isolated hepatocytes from rats ingesting ethanol chronically

Summary Isolated hepatocytes from rats consuming ethanol (8.5 g/kg) daily produce malondialdehyde in significantly higher amounts than liver cells from control animals. The release of LDH and the uptake of trypan blue in both types of hepatocytes do not differ during the incubation period of 2 h. GLDH, however, is only set free into the medium from liver cells of ethanol drinking rats, indicating that mitochondrial alterations are involved.Bomotrichloromethane (CBrCl₃) promotes lipid peroxidation in hepatocytes from ethanol drinking rats in a much higher degree than in cells from control rats. The cell damage induced by CBrCl₃ and indicated by a release of LDH and GLDH from the hepatocytes and their uptake of trypan blue is also much more pronounced in liver cells from ethanol drinking animals.The stronger action of CBrCl₃ cannot be explained by an enhanced microsomal metabolism, because no increase of drug metabolizing enzymes could be observed. The relatively low ethanol consumption did not influence body growth and liver weight and did not evoke any triglyceride accumulation.The normal balance between processes favouring lipid peroxidations and reactions protecting the liver cells seems to be shifted to a state during alcohol intake which promotes formation of radicals.     

Ethanol dependence produced in rats by nutritionally complete diets

Nutritionally complete diets formulated according to American Institute of Nutrition guidelines were used to make rats dependent upon ethanol. When intubated with a diet-ethanol solution for four days rats maintained initial body weight. When forced to consume the solution as the sole source of nutrients and water for nineteen days, rats gained weight. All animals developed severe withdrawal signs as measured by the intensity of tremors ans spatic rigidity. The diet ingredients did not alter the absorption of the ethanol. The results demonstrate that physical dependence on ethanol can be induced in the rat without nutritional impairment.     

Muricide induced by thiamine deficiency in the rats (author's transl)

The emotional behavioral aspects and the interaction between the changes of the polyamine contents and muricide response in thiamine deficient rats were investigated. In the thiamine deficient group, there was evidence of muricide and such increased progressively with advanced thiamine deficient feeding. This muricide was characteristic in the following respects; 1) the killer-rats did not eat but only kill a mouse and it was quite difficult to remove a sacrificed animal from the cage. 2) they bit at random into any body region of the mouse. 3) the killer-rats did not bite inanimate objects such as nails nor chalk. 4) the muricide induced by thiamine deficiency could not be suppressed by a single injection of thiamine HCl. On the 30th day of the experimental feeding, both spermidine and spermine levels in the brain of the thiamine deficient group decreased significantly as compared to the control and the pair-fed groups. Both spermidine and spermine levels were reversed to the control levels with a intraperitoneal administration of thiamine. There were no significant differences in spermine and spermidine levels between the killer-rats and non-killer-rats in the thiamine deficient group.     

Ethanol-reinforced responding and intake as a function of volume per reinforcement.

Number of ethanol reinforcements obtained and ethanol intake (mg/100 g body weight/hr) of 3 food-deprived rats were measured over a range of dipper volumes during daily 1 hr sessions. The rats had free access to water in their home cages between sessions. Ethanol concentration was 8 percent (W/V); each response was reinforced. As the volume per reinforcement increased, ethanol intake tended to increase while the number of reinforcements obtained decreased systematically. Responding was maintained by 8 percent (W/V) ethanol but not by water.     

Effects of long term ethanol consumption mediated oxidative stress on neovessel generation in liver

Angiogenesis, the growth of new blood vessels, is essential during tissue repair. Though most molecular mechanisms of angiogenesis are common to the liver and other organs, there was no report available whether alcoholic liver disease also causes angiogenesis. In this study, we examined the effects of long term ethanol (1.6?g/kg body weight/day) consumption on angiogenic responses in the liver of male Wistar strain albino rats (16–18 weeks old, weighing 200–220?g) up to 36 weeks. Chronic ethanol consumption was associated with not only elevated oxidative stress, and altered cytokines expression, but also developed large von Willebrand factor, fibrosis and activation of matrix metalloproteinases. Moreover, vascular endothelial growth factor-receptor 2 (VEGF-R2, fetal liver kinase 1: Flk-1/KDR) expression and neovessel generation in the rat liver were noted after 36 weeks of ethanol consumption. Thus our study provides novel evidence that long-term ethanol consumption is associated with angiogenesis through delicate and coordinated action of a variety of mediators.     

Changes in Protein,RNA and DNA Content in Various Rat Organs after Long-ter m Intake of Ethanol

Abstract Male Wistar rats were given ethanol (approximately 25% of total caloric intake), while two different control groups were pair-fed isocaloric amounts of lipids or sucrose. After 7-10 weeks the following organs were studied: liver, cerebrum, heart, diaphragm, kidneys and testes. In fasted, ethanol treated rats there was a reduction in the hepatic concentration of RNA and the cerebral RNA/DNA ratio, when compared to both control groups, while no effects were found with respect to organ weight and amounts of protein, RNA or DNA in heart, diaphragm, kidneys and testes. When fed, ethanol treated animals were compared to both control groups, no effects on organ weight and composition were found in any tissue studied. Several significant differences were registered in the ethanol group as compared to one control group only, as well as between the two control groups. The consumption of ethanol (25% of total calories) thus caused only minor alterations in gross organ composition. These results also indicate the importance of interpreting with care any apparent effect of ethanol ingestion, unless at least two different control groups have been employed.     

Ethanol as a reinforcer for rats: Effects of concurrent access to water and alternate positions of water and ethanol

Water and ethanol solutions were concurrently made available on a continuous reinforcement schedule to 4 food-deprived male albino rats during daily 1-hr sessions in an operant conditioning chamber equipped with 2 levers and 2 liquid dippers. The number of ethanol reinforcements substantially exceeded the number of water reinforcements for each rat at each concentration studied (8, 16, and 32% w/v). Water reinforcements were low in number and did not vary with ethanol concentration. As the ethanol concentration was increased, the number of ethanol reinforcements obtained decreased, while the quantity consumed (mg/100 g of body weight/hr) increased. The highest rate of responding occurred at the beginning of the session.     

Ethanol-induced fatty acid ethyl ester formation in vivo and in vitro in rat lung

Fatty acid ethyl esters (FAEE) are the end products of a non-oxidative pathway for ethanol metabolism in a variety of human, rabbit, rat and murine tissues. Our objective was to determine the significance of this pathway in the metabolism of ethanol by the rat lung. In vitro, ¹⁴C-labeled ethyl oleate formation was assayed in the lung and compared with the pancreas, liver, heart and brain. Lipids were extracted with acetone, and ¹⁴C-labeled ethyl oleate was isolated and quantified by thin layer chromatography (TLC) and scintillation spectrometry. FAEE synthetic activity in the lungs (in vitro) was found to be intermediate among the organs examined. In vivo, male rats received 10% ethanol in their drinking water with or without daily i.p. injections of 4-methylpyrazole (1 mmol/kg body wt) for 15 days. Another group of male rats received 4 g/kg body wt ethanol as a 50% (v/v) solution by gavage every 12 h for 2 days. FAEE from the three organs with the highest in vitro activity for FAEE synthesis (pancreas, liver and lung) were extracted with acetone, isolated from normal lipids by TLC and separated by gas chromatography. The lung had lower FAEE-forming activity than the pancreas or the liver in the 15-day studies. However, in the 2-day study, the lung had higher activity than the liver but lower activity than the pancreas. Ethyl oleate, ethyl stearate and ethyl palmitate were the predominant FAEE formed in the intact organism. Ethanol-induced FAEE may play a role in the development of alcohol-related injuries to the lung.     

The influence of thiamine deficiency and ethanol on rat brain catecholamines

In rats treated with a thiamine deficient diet for 30 days the brain content of total thiamine decreased by 27-50%. Thiamine deficiency decreased the dopamine (DA) concentration of the striatum indicating a reduced synthesis of DA. In the hypothalamus the levels of the catecholamine metabolites homovanillic acid (HVA) and 4-hydroxy-3-methoxyphenyl glycol (HMPG) were reduced indicating a reduced DA and noradrenaline (NA) turnover. Animals on a diet containing 5% ethanol had increased concentrations of HVA and HMPG in rest brain indicating an increased DA and NA turnover. The concentration of 1-carboxysalsolinol (1-CSAL) and salsolinol (SAL) in the brain stem was increased in animals receiving ethanol. Thus, both thiamine deficiency and ethanol treatment influenced the catecholamine system in a complex region-dependent way. In the brain regions most susceptible to brain damage in thiamine deficiency, i.e., hypothalamus and brain stem, 1-CSAL and SAL increased most following thiamine deficiency combined with ethanol intake.     

The interaction of ethanol and swimming upon cardiac mass and mitochondrial function

Four groups of female Sprague-Dawley rats received a nutritionally adequate liquid diet formulated for rats. Two groups, one ethanol diet and one control diet swam 6 days/wk for 6 weeks and were designated swim ethanol (SWM-E) and swim control (SWM-C) respectively. Their swimming time increased from 15 min/day on the first day to 2 hrs/day during the final week. One sedentary group received an ethanol diet (SED-E) while another sedentary group received a control diet (SED-C). In the ethanol diet 35% of the calories as ethanol isoenergetically replaced dextrin. The group mean body weights were not different at the end of 6 weeks. The left ventricles of both swimming groups showed similar gains in weight, 13% for the ethanol and 15% for the control. Mitochondrial respiration in the ethanol groups showed a significant depression across substrates and across both populations of mitochondria (subsarcolemmal and intermyofibrillar). The swimming-ethanol interaction in the SWM-E group caused an atrophy of the gastrocnemius-plantaris muscle as evidenced by the 13% loss in weight of the muscle. We conclude that chronic ingestion of ethanol will suppress mitochondrial respiration in sedentary and swimming exercised rats, but will not suppress cardiac hypertrophy in the swimming exercised rats. Muscles that are not chronically overloaded by swimming, such as the gastrocnemius-plantaris muscles will undergo atrophy during the swimming protocol of 6 weeks.     

Effect of Piper betel on Blood Glucose and Lipid Profiles in Rats After Chronic Ethanol Administration

Betel leaf chewing in India is an old tradition. The present study was designed to evaluate the effect of Piper betel Linn. (Piperaceae) leaf extract on glucose, cholesterol, triglycerides, free fatty acids, and phospholipids in rats subjected to chronic ethanol administration. Administration of ethanol (7.9 g/kg body weight) for 60 days resulted in a significant reduction in blood glucose levels and an elevation of serum and tissue (liver and kidney) lipids, as compared to normal control. Subsequent to the experimental induction of toxi-city (i.e., the initial period of 30 days) P. betel extract was simultaneously administered in three different doses (100, 200, and 300 mg/kg body weight) for 30 days along with the daily dose of alcohol. Co-administration of P. betel significantly increased blood glucose and lowered the levels of plasma and tissue lipids as compared to ethanol-treated rats. The leaf extract, at 300 mg/kg, showed a greater hypolipidemic effect than the 100 and 200 mg/kg doses. These results suggest that P. betel leaf extract exhibits a hypolipidemic effect in ethanol-treated rats.     

Reduced Inactivation of Tyrosine Aminotransferase in the Perfused Rat Liver in the Presence of Ethanol

Abstract Livers from fasted male rats (250–300 g body weight) were isolated and perfused. The effect of ethanol in the perfusate (approximate concentration 0.2 (w/v)) on the activity of tyrosine aminotransferase was investigated in the presence and absence of dexamethasone (final concentration 20 (μ/ml) and/or cycloheximide (final concentration 25 μg/ml). The following observations were made: (1) Ethanol increased tyrosine aminotransferase activity both in the presence and absence of dexamethasone. (2) The addition of ethanol or its main metabolite acetaldehyde to the enzyme assay mixture did not increase enzyme activity. Neither did ethanol reduce the leakage of enzyme from liver to perfusate or bile. (3) Tyrosine aminotransferase activity declined more slowly in ethanol-treated livers than in control livers when protein synthesis was inhibited by cycloheximide. (4) Ethanol did not influence either the activity of another liver enzyme, tryptophan oxygenase, or the radioactivity remaining in labelled proteins 1 hr 30 min. after administration of cycloheximide. It is concluded that ethanol increased tyrosine aminotransferase activity in perfused livers by specific inhibition of enzyme inactivation.     

Female reproduction during chronic ethanol consumption in rats

This study was undertaken to ascertain ovarian function under the conditions of ethanol withdrawal and continued ethanol treatment to distinguish between a temporary delay in ovarian activity and a permanent suppression of ovarian function. Immature rats were fed the following diets for 16 weeks: a liquid diet containing 5% ethanol, a liquid diet without ethanol (pair-fed controls), a liquid diet with 5% ethanol for eight weeks followed by laboratory chow and water for eight weeks, or chow and water ad lib. Vaginal patency was significantly delayed in both groups of ethanol-treated rats compared to controls. The duration of an estrous cycle for the rats in the ad lib group was 5.0±0.3 days, while a “regular” estrous cycle was four to six days in duration. The rats which received ethanol for 16 weeks exhibited more irregular estrous cycles (both<4 and >6 days) than the rats with other treatments and the cycles were significantly longer. After 16 weeks of treatment, the rats were mated; ethanol was not given during pregnancy. The average number of pups per litter and body weight of the offspring were similar for all groups. These data show that although ethanol alters normal cyclic activity, it does not totally suppress ovarian function since alcohol-treated rats were capable of mating and delivering viable offspring.     

Antioxidant effect of 2-hydroxy-4-methoxy benzoic acid on ethanol-induced hepatotoxicity in rats

Alcoholic liver disease (ALD) is one of the most common diseases in society. A large number of studies are in progress to identify natural substances that are effective in reducing the severity of ALD. 2-Hydroxy-4-methoxy benzoic acid (HMBA), the active principle of Hemidesmus indicus, an indigenous Ayurvedic medicinal plant in India, is expected to significantly inhibit the development of liver injury in ethanol administration. It is expected to reduce the severity of liver damage in terms of body weight, hepatic marker enzymes, oxidative stress, antioxidant status and histological changes in ethanol-induced hepatotoxic rats. Hepatotoxicity was induced by administering 20% ethanol (5 g kg(-1) daily) for 60 days to male Wistar rats, which resulted in significantly decreased body weight and an increase in liver-body weight ratio. The liver marker enzymes aspartate transaminase, alanine transaminase, alkaline phosphatase, gamma-glutamyl transpeptidase and lactate dehydrogenase were elevated. In addition, the levels of plasma, erythrocyte and hepatic thiobarbituric acid reactive substances, hydroperoxides and conjugated dienes were also elevated in ethanol-fed rats as compared with those of the experimental control rats. Decreased activity of superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, vitamin C and alpha-tocopherol was also observed on alcohol administration as compared with experimental control rats. HMBA was co-administered at a dose of 200 mug kg(-1) daily for the last 30 days of the experiment to rats with alcohol-induced liver injury, which significantly increased body weight, significantly decreased the liver-body weight ratio, transaminases, alkaline phosphatase, gamma-glutamyl transpeptidase and lactate dehydrogenase, significantly decreased the levels of lipid peroxidative markers, significantly elevated the activity of enzymic and non-enzymic antioxidants in plasma, erythrocytes and liver and also increased levels of plasma and liver vitamin C and alpha-tocopherol at the end of the experimental period as compared with untreated ethanol-administered rats. The histological changes were also in correlation with the biochemical findings. The results suggest that HMBA administration may afford protection against ethanol-induced liver injury in rats.