Alcohol linked to enhanced angiogenesis in rat model of choroidal neovascularization

One of the pathologic complications of exudative (i.e. wet-type) age-related macular degeneration (AMD) is choroidal neovascularization (CNV). The aim of this study was to investigate whether chronic and heavy alcohol consumption influenced the development of CNV in a rat model. The oxidative metabolism of alcohol is minimal or absent in the eye, so that ethanol is metabolized via a nonoxidative pathway to form fatty acid ethyl esters (FAEE). Fatty acid ethyl ester synthase (FAEES) was purified from the choroid of Brown Norway (BN) rats. The purified protein was 60 kDa in size and the antibody raised against this protein showed a single band on western blot. BN rats on a regular diet were fed alcohol for 10 weeks. Control rats were fed water with a regular diet and pair-fed control rats were fed regular diet, water and glucose. We found that FAEES activity was increased 4.0-fold in the choroid of alcohol-treated rats compared with controls. The amount of ethyl esters produced in the choroid of 10 week alcohol-fed rats was 7.4-fold more than rats fed alcohol for 1 week. The increased accumulation of ethyl esters was associated with a 3.0-fold increased expression of cyclin E and cyclin E/CDK2; however, the level of the cyclin kinase inhibitor, p27Kip, did not change. The increased accumulation of ethyl esters was also associated with 3.0-fold decreased expression of APN in the choroid. We also found that the size of CNV increased by 28% in alcohol-fed rats. Thus, our study showed that chronic, heavy alcohol intake was associated with both an increased accumulation of ethyl esters in the choroid and an exacerbation of the CNV induced by laser treatment. These results may provide insight into the link between heavy alcohol consumption and exudative AMD.     

Prevention of chronic alcohol and nicotine-induced azospermia,sterility and decreased libido,by a novel tri-substituted benzoflavone moiety from Passiflora incarnata Linneaus in healthy male rats

Excessive long term consumption of alcohol and nicotine have serious detrimental effects upon the libido, fertility, and sperm count in male species. The present work describes the beneficial effects of a novel tri-substituted benzoflavone moiety (BZF) isolated from Passiflora incarnata Linneaus, the phyto-chemical isolation, spectroscopic elucidation, and multifarious biological activities of which have recently been reported by the authors. The BZF moiety has been reported to increase libido, sperm count, and sexual fertility in 2 years old male rats at 10 mg/kg, po dose, in the one of our previous studies. Presently, the BZF moiety has been evaluated against chronic ethanol- and nicotine-induced decrease in libido, sexual fertility and mating efficiency in healthy male rats. The male rats were given ethanol (3 g/kg, po) A, nicotine (2 mg/kg, sc) N, alcohol-nicotine combinations (AN) alone, and also with 10 mg/kg po dose of BZF (concurrent administrations). These treatments were given for 30 days. At the end of treatments, it was observed that rat groups A, N, and AN had no libido (evaluated by mounting behaviour), declined sperm count, and consequently no mating efficiency or fertility (upon pairing with pro-estrus female rats). However, the rats which were given 10 mg/kg BZF along-with nicotine (NP group), alcohol (AP group), and alcohol-nicotine combination (ANP) exhibited significant libido-oriented mounting behaviour, increased sperm count (significantly comparable to the control group), and increased fertilization potential. The rats having decreased sperm count, libido and fertilization potential due to chronic administration of alcohol, nicotine and alcohol-nicotine combinations, i.e., rats of A, N, and AN groups were again subdivided and were given 10 mg/kg BZF for 7 days. This treatment confirmed that BZF speeds up the restoration of sexuality in rats upon cessation of the administration of substances like alcohol, nicotine and alcohol-nicotine combinations, which have severe detrimental effects upon male sexuality, fertility and vigour. BZF, the strongest inhibitor of aromatase enzyme, when administered concurrently with substances like alcohol and nicotine restores sexual virility, libido and vigour in male rats by maintaining the blood-testosterone levels to be high.     

The Nicotinic α6-Subunit Selective Antagonist bPiDI Reduces Alcohol Self-Administration in Alcohol-Preferring Rats

Cigarettes and alcohol are the most abused substances in the world and are commonly co-abused. Nicotine primarily acts in the brain on nicotinic acetylcholine receptors (nAChR), which are also a target for alcohol. The alpha6 subunit of nAChR is expressed almost exclusively in the brain reward system and may modulate the rewarding properties of alcohol and nicotine. Recently, N,N-decane-1,10-diyl-bis-3-picolinium diiodide (bPiDI) was synthesized as a selective, brain penetrant α6 subunit antagonist that reduces nicotine self-administration. The current study aimed to examine the effects of bPiDI on alcohol self-administration in inbred alcohol-preferring (iP) rats. Adult, male iP rats were trained to self-administer alcohol or sucrose. Once stable responding was achieved, rats were injected with bPiDI (1, 3 mg/kg, i.p.) and tested for self-administration under fixed and progressive ratio schedules of reinforcement. They subsequently underwent extinction, in which no rewards or cues were presented in the operant chambers. Then, they were injected with bPiDI prior to testing for cue-induced reinstatement of reward seeking. bPiDI (3 mg/kg) significantly reduced alcohol self-administration in both fixed and progressive ratios without any effects on sucrose self-administration or locomotor activity. In contrast, bPiDI (3 mg/kg) did not inhibit cue-induced reinstatement of either alcohol or sucrose seeking. The results support the involvement of α6 containing nAChR in reinforcing effects of alcohol, but not relapse to alcohol-seeking, without any impact on responding for a natural reward or general activity. bPiDI may be a potential lead molecule for a therapeutic strategy to limit nicotine and alcohol consumption.     

Tetrahydrobiopterin, a cofactor for NOS, improves endothelial dysfunction during chronic alcohol consumption

We sought to investigate mechanisms that may account for impaired nitric oxide synthase (NOS)-dependent dilatation of cerebral arterioles during alcohol consumption. Our goals were to examine 1) the effect of exogenous application of a cofactor for NOS, i.e., tetrahydrobiopterin (BH4) on the reactivity of pial arterioles during alcohol consumption; and 2) endothelial NOS (eNOS) protein in nonalcohol-fed and alcohol-fed rats. Sprague-Dawley rats were fed liquid diets with or without alcohol for 2-3 mo. We measured in vivo diameter of pial arterioles in response to NOS-dependent agonists (ACh and ADP) and a NOS-independent agonist (nitroglycerin) before and during application of BH4. Blood vessels were then harvested for Western blot analysis of eNOS protein. In nonalcohol-fed rats, ACh and ADP produced vasodilatation, which was impaired in alcohol-fed rats. Vasodilatation to nitroglycerin was similar in both groups of rats. Application of BH4 did not alter vasodilatation in nonalcohol-fed rats but improved impaired vasodilatation in alcohol-fed rats. Also, eNOS protein in cerebral cortex microvessels, the basilar artery, and aorta was not different between nonalcohol-fed and alcohol-fed rats. Thus impaired NOS-dependent vasodilatation during alcohol consumption does not appear to be related to an alteration in eNOS protein but may be related to a deficiency and/or alteration in the utilization of BH4.     

Effects of chronic alcohol consumption on expression levels of APP and Aβ-producing enzymes

Chronic alcohol consumption contributes to numerous diseases, including cancers, cardiovascular diseases, and liver cirrhosis. Epidemiological studies have shown that excessive alcohol consumption is a risk factor for dementia. Along this line, Alzheimer's disease (AD) is the most common form of dementia and is caused by the accumulation of amyloid-β (Aβ plaques in neurons. In this study, we hypothesized that chronic ethanol consumption is associated with pathological processing of APP in AD. To investigate the relationship between chronic alcohol consumption and Aβ production, brain samples from rats fed an alcohol liquid diet for 5 weeks were analyzed. We show that the expression levels of APP, BACE1, and immature nicastrin were increased in the cerebellum, hippocampus, and striatum of the alcohol-fed group compared to the control group. Total nicastrin and PS1 levels were induced in the hippocampus of alcohol-fed rats. These data suggest that the altered expression of APP and Aβ-producing enzymes possibly contributes to the chronic alcohol consumption-mediated pathogenesis of AD.     

The effects of dietary flaxseed on the Fischer 344 rat. III. Protection against CCl(4)-induced liver injury

The hepatotoxic effect of carbon tetrachloride (CCl(4)) administered by gavage at 0.25 ml CCl(4) (1:1 in olive oil) per 100 g body weight was examined 24 h later in regular chow fed (RC) and 10% flax chow fed (FC) male and female Fischer 344 rats. CCl(4)-treated RC rats were subdued, lethargic and unkempt. CCl(4)-treated FC rats were much less affected. CCl(4) treatment resulted in loss of weight in RC and FC rats. In males, the weight loss was 6.7% body mass in RC rats compared to 5.6% body mass in FC rats. In females, the weight loss was 7.5% body mass in both RC and FC rats. While CCl(4) treatment increased the level of the liver injury marker plasma alanine aminotransferase (ALT) in RC rats, this CCl(4) effect was significantly attenuated in FC rats. In male rats, the ALT increase was 435-fold in RC rats and 119-fold in FC rats, over that of their respective controls. In female rats, the ALT increase was 454-fold in RC rats and 381-fold in FC rats, over that of their respective controls. These results provide evidence that flax consumption protects the liver against injury and that the extent of the protection is sex dependent. CCl(4) had no effect on the plasma level of gamma-glutamyltranspeptidase (gammaGT) in RC and FC rats supporting the contention that plasma gammaGT is not a useful marker for acute liver injury which is seen in this model. The activity of gammaGT was increased in the livers of FC rats compared to RC rats: 2.7-fold in males and 1.5-fold in females. In RC rats, the activity of liver gammaGT was decreased by CCl(4) treatment: 70% in the male and 25% in the female. However, this CCl(4) effect was reversed or abolished by flax consumption. Compared to RC rats: in male FC rats, CCl(4) actually increased the activity of liver gammaGT 1.28-fold; while in female FC rats, the depressing effect of CCl(4) treatment was abolished. The flax-induced preservation of gammaGT in the liver in response to injury may be involved in the observed hepatoprotection through generation of GSH. In RC male rats, CCl(4) treatment effected a 25% reduction in plasma glucose levels. There was no decrease in CCl(4)-treated FC male rats. In female rats, CCl(4) treatment effected a 21% decrease in plasma glucose levels in both RC and FC rats. In conclusion, multiple parameters for acute CCl(4)-induced injury were attenuated in the FC compared to the RC rat. That flaxseed consumption conferred greater protection against liver injury in the male than in the female suggests an involvement of the estrogenic lignan component of flaxseed. We discuss the possibility that this hepatoprotection is through a flax lignan-induced increase in reduced glutathione related to a flax effect on the activity of liver gammaGT in the resting state and the maintenance of its activity in response to injury.     

Altered Pattern of Na,K-ATPase Activity and mRNA During Chronic Alcohol Consumption by Juvenile and Adolescent Rats

The effect of chronic ethanol consumption on cerebral cortical activity of Na,K-ATPase was determined in Long-Evans (LE) rats fed an ethanol-containing diet beginning at different stages of development. Na,K-ATPase activity was operationally resolved into α1 and α2/3 isozyme activities. There was no significant difference in Na,K-ATPase activities before and after alcohol consumption in the preparations from adult rats. However, for rats beginning alcohol consumption as adolescents, the α2/3 activity was significantly elevated following chronic alcohol consumption. Both LE and Sprague–Dawley rats showed this same selective increase in cortical α2/3 activity when rats began alcohol consumption as juveniles. The shift in cortical α2/3 activity was not observed in cerebellum or subcortical forebrain and was reversible when rats were fed ethanol throughout the normal adolescent period and then withdrawn and tested 2 weeks later (during the adult period). Levels of isoform-specific mRNA were determined in preparations of cerebral cortices of rats showing elevated α2/3 isozyme activities. In these preparations, isoform specific α2 and α3 mRNA was significantly elevated. There was no effect of ethanol feeding on cortical α1 mRNA. These findings indicate that the longer term effects of ethanol on the developing brain include elevated Na,K-ATPase activity and a mechanism that is pre-translational and isoform specific.     

Temporal effect of alcohol consumption on reactivity of pial arterioles: role of oxygen radicals

Chronic alcohol consumption reduces nitric oxide synthase-dependent responses of pial arterioles via mechanisms that remain uncertain. In addition, the temporal effects of alcohol on pial arterioles is unclear. Thus our goals were to examine the role of oxygen-derived free radicals in alcohol-induced impairment of cerebrovascular reactivity and the temporal effect of alcohol on reactivity of pial arterioles. Sprague-Dawley rats were pair-fed a liquid diet with or without alcohol for 2-3 wk, 2-3 mo, or 5-6 mo. We measured the in vivo diameter of pial arterioles in response to nitric oxide synthase-dependent dilators acetylcholine and ADP and the nitric oxide synthase-independent dilator nitroglycerin. In nonalcohol-fed rats, acetylcholine (1.0 and 10 microM) and ADP (10 and 100 microM) produced dose-related dilatation of pial arterioles. Whereas there was no difference in reactivity of arterioles to the agonists in rats fed the nonalcohol and alcohol diets for a period of 2-3 wk, there was a significant impairment in reactivity of arterioles to acetylcholine and ADP, but not nitroglycerin, in rats fed the alcohol diet for longer durations. We then found that treatment with superoxide dismutase did not alter baseline diameter of pial arterioles in nonalcohol-fed or alcohol-fed rats, but significantly improved impaired nitric oxide synthase-dependent dilatation of pial arterioles in alcohol-fed rats. Thus our findings suggest a temporal relationship in the effects of alcohol on reactivity of pial arterioles and that impaired nitric oxide synthase-dependent cerebral vasodilatation during chronic alcohol consumption may be related, in part, to enhanced release of oxygen-derived free radicals.     

Sleep Quality during Exam Stress: The Role of Alcohol,Caffeine and Nicotine

Academic exam stress is known to compromise sleep quality and alter drug consumption in university students. Here we evaluated if sleeping problems and changes in legal drug consumption during exam stress are interrelated. We used the Pittsburgh Sleep Quality Index (PSQI) to survey sleep quality before, during, and after an academic exam period in 150 university students in a longitudinal questionnaire study. Self-reports of alcohol, caffeine, and nicotine consumption were obtained. The Perceived Stress Questionnaire (PSQ-20) was used as a measure of stress. Sleep quality and alcohol consumption significantly decreased, while perceived stress and caffeine consumption significantly increased during the exam period. No significant change in nicotine consumption was observed. In particular, students shortened their time in bed and showed symptoms of insomnia. Mixed model analysis indicated that sex, age, health status, as well as the amounts of alcohol and caffeine consumed had no significant influence on global sleep quality. The amount of nicotine consumed and perceived stress were identified as significant predictors of diminished sleep quality. Nicotine consumption had a small-to-very-small effect on sleep quality; perceived stress had a small-to-moderate effect. In conclusion, diminished sleep quality during exam periods was mainly predicted by perceived stress, while legal drug consumption played a minor role. Exam periods may pose an interesting model for the study of stress-induced sleeping problems and their mechanisms.     

Influence of 12-week nicotine treatment and dietary copper on blood pressure and indices of the antioxidant system in male spontaneous hypertensive rats

Nicotine treatment and copper (Cu) deficiency have been associated with an increased production of reactive oxygen species that may contribute to the development and/or progression of cardiovascular diseases (CVD). The present study investigated the influence of dietary Cu intake on the response to chronic nicotine treatment in spontaneous hypertensive rats (SHR) with respect to tissue trace mineral levels, several components of the oxidant defense system, and lipid peroxidation rates. SHR weighing 100–110 g were fed a Cu deficient diet (?Cu) (0.5 μg Cu/g) for 14 d prior to nicotine treatment. SHR were inserted with tablets that released nicotine at a rate of 75 μg/h or placebo (control). Following tablet insertion, rats were fed a control diet (+Cu) (12.0 μg Cu/g) or the ?Cu diet. Nicotine treatment lasted for 12 wk. Blood pressure (BP) was higher in nicotine-treated SHR than in control SHR at wk 3; BP was unaffected by diet. BP was higher in +Cu nicotine-treated SHR at wk 6 compared to ?Cu nicotine and control rats. BP was not affected by nicotine or diet at wk 2. Liver, heart, and brain Cu levels and liver, heart, and red cell CuZn superoxide dismutase and plasma ceruloplasmin oxidase activities were lower in the ?Cu SHR than in the +Cu SHR. Liver Fe levels were higher and plasma Fe levels were lower in the ?Cu rats than in the +Cu rats. Liver selenium-dependent-glutathione peroxidase (Se-GSH-Px) activity was lower in the ?Cu rats than in the +Cu rats; heart and thoracic aorta Se-GSH-Px activity was unaffected by ?Cu diet. Thoracic aorta, liver, and heart GSH-reductase activities were unaffected by treatments. Plasma thiobarbituric acid reactive substances (TBARS) were higher in the ?Cu than in the +Cu SHR. Liver and heart TBARS production was similar among the groups. These data show that nicotine can exacerbate the development of high BP in susceptible individuals; Cu deficiency did not exacerbate the effects of nicotine.     

Prenatal Alcohol Exposure Increases Postnatal Acceptability of Nicotine Odor and Taste in Adolescent Rats

Human studies indicate that alcohol exposure during gestation not only increases the chance for later alcohol abuse, but also nicotine dependence. The flavor attributes of both alcohol and nicotine can be important determinants of their initial acceptance and they both share the component chemosensory qualities of an aversive odor, bitter taste and oral irritation. There is a growing body of evidence demonstrating epigenetic chemosensory mechanisms through which fetal alcohol exposure increases adolescent alcohol acceptance, in part, by decreasing the aversion to alcohol''s bitter and oral irritation qualities, as well as its odor. Given that alcohol and nicotine have noteworthy chemosensory qualities in common, we investigated whether fetal exposure to alcohol increased the acceptability of nicotine''s odor and taste in adolescent rats. Study rats were alcohol-exposed during fetal development via the dams'' liquid diet. Control animals received ad lib access to an iso-caloric, iso-nutritive diet throughout gestation. Odorant-induced innate behavioral responses to nicotine odor (Experiment 1) or orosensory-mediated responses to nicotine solutions (Experiment 2) were obtained, using whole-body plethysmography and brief access lick tests, respectively. Compared to controls, rats exposed to fetal alcohol showed an enhanced nicotine odor response that was paralleled by increased oral acceptability of nicotine. Given the common aversive component qualities imbued in the flavor profiles of both drugs, our findings demonstrate that like postnatal alcohol avidity, fetal alcohol exposure also influences nicotine acceptance, at a minimum, by decreasing the aversion of both its smell and taste. Moreover, they highlight potential chemosensory-based mechanism(s) by which fetal alcohol exposure increases the later initial risk for nicotine use, thereby contributing to the co-morbid expression with enhanced alcohol avidity. Where common chemosensory mechanisms are at play, our results suggest broader implications related to the consequence of fetal exposure with one substance of abuse and initial acceptability of others.     

Effects of dietary nicotine and partial starvation of tobacco hornworm,Manduca sexta, on the survival and development of the parasitoidCotesia congregata

A factorial experiment tested the effects of dietary nicotine and of partial starvation of fifth instar tobacco hornworm,Manduca sexta (L.) (Lepidoptera: Sphingidae), on the survival and development of the parasitoidCotesia congregata (Say) (Hymenoptera: Braconidae) in the laboratory. More parasitoids failed to emerge from partially starved hosts when reared on 0.1% nicotine diet, than from partially starved hosts fed control diet. Parasitoids reared from hornworms starved by 75% on nicotine diet had the longest development. The number of wasps was reduced when reared from hosts that were fed less than 50% of their daily consumption on nicotine diet. Pupal mortality was increased by dietary nicotine. Nicotine, within the host tissues, may be directly toxic to the parasitoids before their emergence from hornworms. Our data suggest that nicotine may act by mediating the availability of nutrients or reduce assimilation of nutrients by developing parasitoids.     

Soy protein isolate induces CYP3A1 and CYP3A2 in prepubertal rats

Feeding soy diets has been shown to induce cytochrome P450s in gene family CYP3A in Sprague-Dawley rat liver. We compared expression of CYP3A enzymes on postnatal Day 33 (PND33) rats fed casein or soy protein isolate (SPI+)-based AIN-93G diets continuously from gestational Day 4 through PND33 or the diets were switched on PND15 (n = 3-6 litters) to examine the potential imprinting effects of soy on drug metabolism. In addition rats were fed casein, SPI+, SPI+ stripped of phytochemicals (SPI-), or casein diets supplemented with the soy-associated isoflavones genistein or daidzein from weaning through PND33 to examine the hypothesis that the isoflavones are responsible for CYP3A induction by soy feeding. Feeding SPI either continuously or from weaning induced hepatic CYP3A1 and CYP3A2 mRNA, apoprotein, and CYP3A-dependent testosterone 6beta-hydroxylase activity in liver microsomes 2- to 5-fold (P < 0.05). CYP3A mRNA expression was also elevated 2- to 3-fold in the jejunum of SPI-fed rats (P < 0.05). CYP3A was not induced in livers of rats switched to casein from soy at weaning. Induction of CYP3A1 also did not occur in rats fed SPI-, but CYP3A2 mRNA and apoprotein were induced (P < 0.05) in females fed SPI-. Offspring weaned onto genistein-supplemented diets had no elevation of CYP3A mRNAs or apoproteins. Weaning onto daidzein diets increased CYP3A2 mRNA and apoprotein expression in male rats (P < 0.05). These data suggest that early soy consumption may increase the metabolism of a wide variety of CYP3A substrates, but that soy does not imprint the expression of CYP3A enzymes. Effects on CYP3A1 expression appear to be primarily due to phytochemical components of SPI other than isoflavones. In contrast, consumption of soy protein and daidzein appear to be associated with the induction of CYP3A2.     

Ghrelin Receptor (GHS-R1A) Antagonism Suppresses Both Alcohol Consumption and the Alcohol Deprivation Effect in Rats following Long-Term Voluntary Alcohol Consumption

Alcohol dependence is a heterogeneous disorder where several signalling systems play important roles. Recent studies implicate that the gut-brain hormone ghrelin, an orexigenic peptide, is a potential mediator of alcohol related behaviours. Ghrelin increases whereas a ghrelin receptor (GHS-R1A) antagonist decreases alcohol consumption as well as operant self-administration of alcohol in rodents that have consumed alcohol for twelve weeks. In the present study we aimed at investigating the effect of acute and repeated treatment with the GHS-R1A antagonist JMV2959 on alcohol intake in a group of rats following voluntarily alcohol consumption for two, five and eight months. After approximately ten months of voluntary alcohol consumption the expression of the GHS-R1A gene (Ghsr) as well as the degree of methylation of a CpG island found in Ghsr was examined in reward related brain areas. In a separate group of rats, we examined the effect of the JMV2959 on alcohol relapse using the alcohol deprivation paradigm. Acute JMV2959 treatment was found to decrease alcohol intake and the effect was more pronounced after five, compared to two months of alcohol exposure. In addition, repeated JMV2959 treatment decreased alcohol intake without inducing tolerance or rebound increase in alcohol intake after the treatment. The GHS-R1A antagonist prevented the alcohol deprivation effect in rats. There was a significant down-regulation of the Ghsr expression in the ventral tegmental area (VTA) in high- compared to low-alcohol consuming rats after approximately ten months of voluntary alcohol consumption. Further analysis revealed a negative correlation between Ghsr expression in the VTA and alcohol intake. No differences in methylation degree were found between high- compared to low-alcohol consuming rats. These findings support previous studies showing that the ghrelin signalling system may constitute a potential target for development of novel treatment strategies for alcohol dependence.     

Efficacy of providing nicotine in a liquid diet to rats.

To determine if rats would consume nicotine at psychoactive levels, a nutritionally balanced diet with 0, 20, 60, or 200 mg of nicotine tartrate per kg of diet was provided. Diet consumption and body weight differences were recorded for 14 days after which, following 16 hr of withdrawal, animals were given access to a two-bottle choice of the previously presented diet and a nicotine-free diet. Spontaneous horizontal motor activity was recorded 8, 16, and 24 hr after withdrawal. By Day 14, all animals showed a significant increase in diet consumption and significant weight gain compared to Day 1. Animals consumed an average of 2.1, 6.8, or 19.5 mg/kg/day of nicotine on the low, medium, and high-nicotine diets, respectively. However, animals receiving the high-nicotine diet consumed less diet and gained less weight than the control, low, and medium nicotine groups. During only the first 4 hr of the two-bottle choice (16-20 hr postwithdrawal), the high-nicotine group consumed significantly higher amounts of nicotine base than the other groups, but also consumed more of the control diet during the first 2 hr. In a replicate experiment, animals receiving the medium-nicotine diet showed an increased consumption of the nicotine diet and increased preference for nicotine following a 14-day exposure compared to the control-fed animals and compared to a baseline preference test. Also, this group showed differences in locomotor activity consistent with other studies using an injection regimen or subcutaneuos pumps to induce dependence. Finally, animals in all three groups exhibited high plasma nicotine and cotinine (a major nicotine metabolite) levels. Because animals in all groups tolerated the diet well, gained weight, selected the nicotine diet in a choice test, and showed withdrawal symptoms, we conclude that the liquid diet proved to be a satisfactory method of inducing nicotine dependence in rats.     

Effects of live Lactobacillus paracasei on plasma lipid concentration in rats fed an ethanol-containing diet

The protective effects of live Lactobacillus paracasei NFRI 7415 on alcoholic liver disease were investigated. Male Fischer 344 rats were fed a control diet (CD), an ethanol diet (ED) (35.8% of total energy from ethanol), or an ethanol diet containing 20% live Lb. paracasei NFRI 7415 (10(7) cfu/g) (LD) for 10 weeks. The results indicated that live Lb. paracasei NFRI 7415 reduced the total cholesterol concentration of the plasma and liver in the rats fed the LD. The level of docosahexaenoic acid (DHA; 22:6n-3) in the plasma and liver of the LD group was higher than in the ED group. Chronic alcohol consumption decreased the level of n-3 fatty acid in the plasma and liver of the ED group. These results indicated that live Lb. paracasei NFRI 7415 can adjust the fatty acid composition of the plasma and liver, and that it is possible to decrease liver damage due to chronic alcohol intake.     

Possible correlations between the level of alcoholic motivation and the electrophysiological structure of sleep in the rat

Using modified Porsolt's method, the electrophysiological sleep pattern was studied in normal conditions and after a single intraperitoneal ethanol injection to noninbred male albino rats divided into 2 groups ("high activity" and "low activity" rats). Voluntary alcohol intake in these rats was measured during free choice between 10% ethanol and water for 20 days. "Low activity" rats were characterized by a statistically significant 3.4-fold higher level of ethanol consumption and 2.7-fold longer REM-sleep stage, as compared to "high activity" animals. In "low activity" animals ethanol (1 g/k, 10% solution, i. p.) inhibits and in "high activity" rats it increases REM-sleep stage, thus removing differences in the sleep pattern in the two groups of rats. The data obtained suggest a possible role of REM-sleep in the development of alcohol motivation.     

Estrogens and phytoestrogens: brain plasticity of sexually dimorphic brain volumes

Sexually dimorphic brain volumes (sexually dimorphic nucleus of the preoptic area (SDN-POA) and anteroventral periventricular (AVPV) nucleus) are influenced by estrogens. Phytoestrogens, derived from plants (especially soy products), are molecules structurally and functionally similar to estradiol. The purpose of this study was to examine: the consumption of phytoestrogen (using a phytoestrogen-rich (Phyto-600) versus a phytoestrogen-free (Phyto-free)) diets from conception to adulthood (or changing the diets during adulthood) and characterizing (a) circulating plasma phytoestrogen levels, (b) testosterone levels in males, (c) sexually dimorphic brain volumes (i.e. the SDN-POA and AVPV) and (d) the presence of apoptotic cells in these brain structures in Long-Evans rats. Phyto-600 fed animals displayed total serum phytoestrogens levels 37-fold higher compared to Phyto-free values. Circulating testosterone levels were not significantly altered by the diets. Female SDN-POA volumes were not altered by the diets. Whereas, males fed a Phyto-free diet displayed decreased SDN-POA volumes compared to male Phyto-600 values. Females fed the Phyto-600 diet displayed larger AVPV volumes compared to males on the same diet or females on the Phyto-free diet. Males fed the Phyto-free diet had the largest AVPV values compared to Phyto-600 fed males. When the SDN-POA region was examined in lifelong Phyto-free fed males, apoptotic cells were present versus males fed the Phyto-600 diet and in the AVPV region the opposite results were obtained. In summary, consumption of dietary phytoestrogens (estrogen mimics) can alter hormone-sensitive hypothalamic brain volumes in rodents during adulthood.     

Attachment of rat hepatocytes to plastic substrata in the absence of serum requires protein synthesis.

Female rats were pair-fed nutritionally adequate liquid diets containing either ethanol (36 % of total cal.) or isocaloric carbohydrates (controls) for 4 weeks. Compared to controls, chronic alcohol consumption led to slightly increased activities of various hepatic enzymes in the serum. Paracetamol administered 18 hours after ethanol withdrawal resulted within 18 hours in a significant increase of serum GOT and GPT activities, which was much more pronounced in rats fed ethanol chronically than in their pair-fed controls. Thus, chronic alcohol consumption predisposes to increased hepatotoxicity due to paracetamol.     

Taurine: Protective properties against ethanol-induced hepatic steatosis and lipid peroxidation during chronic ethanol consumption in rats

Summary Alcohol was administered chronically to female Sprague Dawley rats in a nutritionally adequate totally liquid diet for 28 days. This resulted in hepatic steatosis and lipid peroxidation. Taurine, when co-administered with alcohol, reduced the hepatic steatosis and completely prevented lipid peroxidation. The protective properties of taurine in preventing fatty liver were also demonstrated histologically. Although alcohol was found not to affect the urinary excretion of taurine (a non-invasive marker of liver damage), levels of serum and liver taurine were markedly raised in animals receiving alcohol + taurine compared to animals given taurine alone. The ethanol-inducible form of cytochrome P-450 (CYP2E1) was significantly induced by alcohol; the activity was significantly lower than controls and barely detectable in animals fed the liquid alcohol diet containing taurine. In addition, alcohol significantly increased homocysteine excretion into urine throughout the 28 day period of ethanol administration; however, taurine did not prevent this increase. There was evidence of slight cholestasis in animals treated with alcohol and alcohol + taurine, as indicated by raised serum bile acids and alkaline phosphatase (ALP). The protective effects of taurine were attributed to the potential of bile acids, especially taurine conjugated bile acids (taurocholic acid) to inhibit the activity of some microsomal enzymes (CYP2E1). Thesein vivo findings demonstrate for the first time that hepatic steatosis and lipid peroxidation, occurring as a result of chronic alcohol consumption, can be ameliorated by administration of taurine to rats.