Impact of zinc supplementation on the improvement of ethanol tolerance and yield of self-flocculating yeast in continuous ethanol fermentation

The effects of zinc supplementation were investigated in the continuous ethanol fermentation using self-flocculating yeast. Zinc sulfate was added at the concentrations of 0.01, 0.05 and 0.1 g l(-1), respectively. Reduced average floc sizes were observed in all the zinc-supplemented cultures. Both the ethanol tolerance and thermal tolerance were significantly improved by zinc supplements, which correlated well with the increased ergosterol and trehalose contents in the yeast flocs. The highest ethanol concentration by 0.05 g l(-1) zinc sulfate supplementation attained 114.5 g l(-1), in contrast to 104.1 g l(-1) in the control culture. Glycerol production was decreased by zinc supplementations, with the lowest level 3.21 g l(-1), about 58% of the control. Zinc content in yeast cells was about 1.4 microMol g(-1) dry cell weight, about sixfold higher than that of control in all the zinc-supplemented cultures, and close correlation of zinc content in yeast cells with the cell viability against ethanol and heat shock treatment was observed. These studies suggest that exogenous zinc addition led to a reprogramming of cellular metabolic network, resulting in enhanced ethanol tolerance and ethanol production.     

Influence of zinc on the status of hepatic trace elements and biokinetics of 65Zn in ethanol treated rats

Whole body counting studies of 65Zn indicated that the Tb1 (the faster component) was significantly decreased while the slower component (Tb2) was increased significantly following ethanol treatment. Interestingly, following zinc treatment to ethanol treated rats, slower component (Tb2) of 65Zn came back to within normal limits while the faster component (Tb1) got significantly elevated in comparison to ethanol treatment. Percent uptake values of 65Zn were found to be increased in liver, intestine, muscle, brain and kidney, and decreased in bone under alcoholic conditions. Interestingly, the uptake values of 65Zn in all the organs except muscle were reverted back to within normal limits upon zinc supplementation to these ethanol intoxicated animals. A significant decrease in zinc contents was noticed in ethanol treated rats, which, however, were raised to normal levels upon zinc supplementation: Copper levels, on the other hand, were significantly enhanced in both ethanol fed and combined ethanol + zinc treated rats. Calcium levels were significantly decreased in both ethanol and zinc treated rats, which however were further reduced upon zinc supplementation to ethanol fed rats. However, no significant change was observed in the concentrations of sodium and potassium in any of the treatment groups. In conclusion, zinc appears to play a protective role by normalizing the turnover of 65Zn in whole body as well as in its uptake in different organs under alcoholic conditions.     

补锌对酒精性肝病的影响及其分子机制

目的:本研究是为了观察饮食补充锌减轻酒精性肝病损伤的作用及与HNF-4α的关系。方法:选用成年C57BL/6小鼠40只,按随机数字表分为4组(n=10):正常对照组、酒精中毒组、正常补锌组及酒精补锌组,用不同饮食喂养6个月处死,在正常补锌组和酒精补锌组小鼠饮用水中加入硫酸锌,使锌的含量达到75 mg/L。取各组小鼠肝组织进行病理切片及增殖细胞核抗原(PCNA)免疫组织化学染色,RT-PCR检测肝细胞核因子-4α(HNF-4α)含量,Western blot检测肝组织HNF-4α蛋白表达,检测"肝组织超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量"。结果:酒精中毒组小鼠HNF-4α转录及表达均明显低于正常对照组,差异具有统计学意义(P<0.05),该组小鼠MDA含量增高,SOD活性下降与正常对照组相比差异有统计学意义(P<0.05);而酒精补锌组小鼠PCNA阳性肝细胞数目及HNF-4α蛋白表达水平明显高于酒精中毒组,差异有统计学意义(P<0.05),该组小鼠SOD活性增加,MDA下降,与酒精中毒组相比差异有统计学意义(P<0.05)。结论:长期酒精喂养导致小鼠氧化还原失衡,而补锌可逆转该状态。我们推测饮食补锌可能是通过增加HNF-4α的转录及表达而增强酒精喂养小鼠的肝再生,因此,饮食补锌可能对酒精性肝病有较好的影响。     

Relative and combined effects of ethanol and protein deficiency on some hair trace elements

This study was performed in order to analyze the relative and combined effects of ethanol and protein deficiency on hair copper, zinc, manganese, and iron content in four groups of seven animals each which were pair-fed during 8 wk with (1) a nutritionally adequate diet, (2) a 36% (as energy) ethanol-containing isocaloric diet, (3) a 2% protein, isocaloric diet, and (4) a 36% ethanol, 2% protein isocaloric diet, respectively, following the Lieber-DeCarli model, and to analyze the relationship between hair copper, zinc, manganese, and iron content, and the liver and muscle content of these elements. Although there was a trend to higher levels of all the elements analyzed in the the hair of the low-protein fed animals, differences were statistically significant regarding copper and manganese, effects being solely attributable to the low protein diet, not to ethanol. Moreover, hair copper was significantly, inversely related with final weight and weight loss. There were significant relationship between liver zinc and muscle zinc (r=0.57, p=0.002), but not between liver or muscle zinc and hair zinc; no correlations were observed between muscle copper and hair copper, nor between liver manganese and hair manganese. An inverse, statistically significant correlation was observed between liver copper and hair copper (r=−0.39, p<0.05).     

Alterations induced by chronic ethanol treatment on lipid composition of microsomes, mitochondria and myelin from neonatal chick liver and brain

The effect of 18 days ethanol consumption on the lipid composition of microsomes, mitochondria and myelin have been studied in neonatal chick liver and brain. Neither cholesterol nor phospholipid content was modified in both liver microsomes and mitochondria. However, cholesterol content of brain microsomes, mitochondria and myelin was clearly increased, mainly due to an enhancement of free cholesterol. Likewise, ethanol consumption induced a clear increase of phospholipid content in brain mitochondria and myelin. As a consecuence of these changes, the cholesterol/phospholipid molar ratio strongly increased only in the myelin fraction. The myelin phospholipid composition markedly varied by ethanol treatment. Our results indicate that the maximal modifications were induced by ethanol in membranes with a high cholesterol content, suggesting that differences in the chemical composition of membranes could be responsible for differences in the response to the ethanol consumption.     

Topographic determination of zinc in human brain by atomic absorption spectrophotometry

Atomic absorption spectroscopy was used for measuring the zinc content, in ppb (μg/1), of brain tissue. A new method for determining the correction factor of atomic absorption interference is described. Measurements of the zinc content of twenty-four regions of adult human brains showed the maximum zinc content in resistent sector and endplate of the Amnion's horn, corroborating the histochemical data. The distribution of zinc in other regions was relatively uniform, but white matter showed lower values than gray matter. The zinc content of seventeen regions of human newborn brains was below that in adult brains, for all regions. The blood content of brain tissue contributed only insignificantly to its zinc content.     

Effect of excess dietary histidine on rate of turnover of65Zn in brain of rat

The effect of the chronic administration of histidine on the brain zinc level was examined in growing, male Wistar rats. Using a purified diet, the minimum zinc requirement for normal growth and normal plasma and tissue zinc levels was found to be around 10 ppm. Given this zinc content; the diet was supplemented with 5% and 8% histidine, respectively, or with 10% glycine (as control). Brain zinc was analyzed by measuring the rate of turnover of⁶⁵Zn from 2–4 weeks after a single injection of the tracer. Feeding the diet supplemented with 5% histidine caused a small decrease in the plasma zinc concentration and a slight increase in the rate of turnover of⁶⁵Zn in the cerebrum and the cerebellum as compared to the control group. The animals fed the diet supplemented with 8% histidine became severely zinc deficient (as evidenced by a 50% reduction in the plasma zinc content), however, the rate of turnover of⁶⁵Zn in all brain regions examined was significantly decreased as compared to the control group. The results indicate that histidine has no specific complexing action on the brain zinc.     

Serotonin content in different sections of the brain, liver, intestines and blood of rats predisposed and not predisposed to alcohol consumption

Experiments were made with white random-bred rats (males) exposed to ethanol. The content of serotonin measured by spectrofluorometry was higher in the hypothalamus, brain stem and intestine, and was lower in the thalamus, striatum liver and blood in the animals predisposed to voluntary alcohol consumption and with lateral position duration 62 +/- 18 min as compared with the animals not predisposed to alcohol consumption and with lateral position duration 196 +/- 23 min, the dose of ethanol being 4.5 g/kg i. p. Thirty minutes after ethanol administration in a dose of 2.5 g/kg i. p. to the alcohol-predisposed rats there was a lowering of the serotonin content in the hypothalamus and an increase in the thalamus, brain stem, liver and blood. Meanwhile in the rats not predisposed to alcohol consumption, the serotonin content rose in the hypothalamus, brain stem, liver, intestine and blood and fell in the thalamus and striatum. It is assumed that the serotoninergic system of the brain may play a role in the formation of "positive" or "negative" attitudes to ethanol in the population of white random-bred rats.     

Biochemical response to cadmium

The effect of daily oral administration of ethanol (2.5, 5, or 10% in drinking water for 8 wk), lead (10 mg/kg, po, once daily for 8 wk), or their combination on tissue trace-metal concentration and hematopoietic and hepatic biochemical indices was investigated in male rats. Ethanol (10%) ingestion enhanced the hepatic lipid peroxidation and decreased the calcium and magnesium content of blood and liver. Coexposure to lead and ethanol (5 and 10%) produced a more pronounced elevation of blood zinc protoporphyrin (ZPP) and hepatic lipid peroxidation. Combined lead-ethanol exposure also lowered the concentration of blood and hepatic magnesium and calcium and increased the amount of lead in the blood, liver, and brain compared to a group treated with lead alone. The results suggest that chronic alcohol ingestion results in calcium and magnesium loss. However, coexposure to lead and ethanol could result in more serious depletion of calcium and magnesium, and this could be the cause of suspected synergism between alcohol consumption and lead poisoning.     

The effects of chronic alcohol and vitamin E consumption on aging pigments and learning performance in mice

Chronic ethanol consumption further accelerates age-related impairment of shuttle box avoidance learning in mice. The hypothesis was tested that the behavioral impairment is a result of brain lipofuscin pigment deposition, which may be accelerated by ethanol consumption and prevented by the antioxidant effects of pharmacological doses of vitamin E. Feeding an ethanol-containing liquid diet for 5 months did not increase the lipofuscin content when compared with mice pair-fed a liquid diet containing isocaloric amounts of sucrose or standard solid laboratory food containing nutritionally adequate amounts of vitamin E. Supplementation of diets with vitamin E decreased brain lipofuscin content in all groups but failed to prevent the age- or ethanol-induced learning deficit. There was no effect of chronic ethanol consumption on brain weights, DNA, RNA, or protein content.It is concluded that the age-related impairment of avoidance learning is accelerated by chronic alcohol consumption. At the molecular level this acceleration is not caused by an increased brain lipofuscin deposition nor is it prevented by the antioxidant effects of vitamin E.     

高压氧预处理对减压病脑组织MMP-9表达与相关元素关系研究

目的:探讨高压氧预处理对减压病大鼠脑组织基质金属蛋白酶-9(matrix metalloproteinases-9,MMP-9)蛋白的表达与相关金属元素的关系。方法:雄性SD大鼠36只,随机分为正常对照组(NC group)、减压组(DCS group)、HBO预处理组(HBO-PC group),每组12只。连续进行高压氧(hyperbaric oxygen,HBO)预处理5天后建立减压病模型,原子吸收分光光度计测定各组大鼠脑组织元素锰、锌、铁和镁的含量;免疫组织化学法测定MMP-9蛋白表达,并对两者的结果做相关性分析。结果:减压组镁、锌、铁的含量降低,高压氧预处理组锌、镁含量降低而锰、铁的含量升高(P0.05);与减压组相比,高压氧预处理组锰、锌、铁、镁含量均升高(P0.05);减压组中MMP-9表达较对照组明显增加(P0.05),高压氧预处理组MMP-9表达被抑制,与减压组相比明显减少(P0.05);脑组织MMP-9阳性细胞表达数与相关的金属元素锌、镁含量呈负相关(P0.05)。结论:金属元素锌、镁的含量与MMP-9的表达在减压病发生过程中起着非常重要的作用,高压氧预处理可以通过调节元素锌与镁的含量与MMP-9的表达来抑制减压病发生时的大鼠脑组织的氧化损伤,从而起到对减压病的保护作用。     

The effects of alcohol on cyclic AMP in mouse brain

Detailed analysis of the dose-response and time-course relationship of ethanol to changes in adenosine 3,5-cyclic monophosphate (cAMP) content of mouse brain revealed several patterns of response, including both decreases and increases depending on brain area. Whole-brain cAMP content was decreased with ethanol injection at all doses (0.4–3.2 g/kg), and reflected the decreased levels in the cortex. The subcortical and cerebellar levels underwent a significant increase with doses of 1.6 and 3.2 g/kg, respectively. In all brain areas, significant changes in cAMP content occur within 10 min after ethanol injection; elevated levels persist for 30–60 min in the subcortex and cerebellum, but remain significantly depressed in the cortex at 3 h. These dynamic changes in brain cAMP levels after ethanol administration may reflect variations in neurotransmitter activity.     

Differential response of chick liver and brain membranes to short ethanol treatment

The effect of 60 hr ethanol ingestion on lipid composition of liver and brain membranes from 2-day-old chicks was investigated. Analysis of hepatic membrane cholesterol shows that ethanol induced a slight increase in microsomes exclusively due to free cholesterol while mitochondria was not affected. In brain, both fractions showed a clear increase in their cholesterol content, while a high decrease was observed in myelin. Free cholesterol was also the main responsible for the changes found in brain. The ethanol-treated animals showed an alteration in their phospholipid composition exclusively in brain microsomes and myelin. Despite all these changes, the values of cholesterol/phospholipid molar ratio in both liver and brain membranes remained unaltered after short ethanol treatment. Our results indicate that neonatal chick brain membranes appears to be especially sensitive to the presence of ethanol.     

小麦和油菜中Cu和Zn的化学结合形态初步研究

1　引　　言微量元素在植物体中的化学结合形态的研究 ,对于充分了解其在植物体内的迁移转化机理 ,以及阐明其生理作用特征等都具有重要意义 .但是 ,至今为止 ,由于植物体内微量元素的化学结合形态比较复杂 ,而且差异很大 ,加上研究方法的限制 ,人们对于微量元素在植物体中存在的化学形态知之甚少 .参照国内外报道的一些资料[1～ 4 ] ,采用连续浸提的方法 ,初步探讨了Ｃｕ和Ｚｎ在小麦和油菜植株中的各种化学形态的含量和分异特征 ,试图阐明其在植物体内各种化学结合形态的差异性规律 ,为明确其在植物体内的转运机理和合理施用微量元素肥料…     

Pre- and Postnatal Exposure to Moderate Levels of Ethanol Can Have Long-Lasting Effects on Hippocampal Glutamate Uptake in Adolescent Offspring

The developing brain is vulnerable to the effects of ethanol. Glutamate is the main mediator of excitatory signals in the brain and is probably involved in most aspects of normal brain function during development. The aim of this study was to investigate vulnerability to and the impact of ethanol toxicity on glutamate uptake signaling in adolescent rats after moderate pre and postnatal ethanol exposure. Pregnant female rats were divided into three groups and treated only with water (control), non-alcoholic beer (vehicle) or 10% (v/v) beer solution (moderate prenatal alcohol exposure—MPAE). Thirty days after birth, adolescent male offspring were submitted to hippocampal acute slice procedure. We assayed glutamate uptake and measured glutathione content and also quantified glial glutamate transporters (EAAT 1 and EAAT 2). The glutamate system vulnerability was tested with different acute ethanol doses in naïve rats and compared with the MPAE group. We also performed a (lipopolysaccharide-challenge (LPS-challenge) with all groups to test the glutamate uptake response after an insult. The MPAE group presented a decrease in glutamate uptake corroborating a decrease in glutathione (GSH) content. The reduction in GSH content suggests oxidative damage after acute ethanol exposure. The glial glutamate transporters were also altered after prenatal ethanol treatment, suggesting a disturbance in glutamate signaling. This study indicates that impairment of glutamate uptake can be dose-dependent and the glutamate system has a higher vulnerability to ethanol toxicity after moderate ethanol exposure In utero. The effects of pre- and postnatal ethanol exposure can have long-lasting impacts on the glutamate system in adolescence and potentially into adulthood.     

Effect of one-time and chronic administration of ethanol on the concentration of beta-endorphin in the brain of rats with different alcoholic motivation

The concentration of beta-endorphin was determined in the cortex of the large hemispheres, thalamus, striatum and medulla oblongata of rats with varying duration of ethanol anesthesia and after a single injection of ethanol (2.5 g/kg). The content of beta-endorphin was also measured in the brain of rats which preferred and rejected 15% ethanol during long-term (up to 10 months) alcoholization. The data obtained indicate that ethanol produces a specific effect on the endorphinergic system in different brain structures of animals predisposed to voluntary alcoholization. A possible involvement of the neuropeptide in the formation of alcohol tolerance and physical dependence is discussed.     

Effect of ethanol on the concentration of serotonin in the brain of the rat and the excretion of 5-hydroxyindoleacetic acid

It is found that serotonin content in the brain areas and heart of rats with low alcohol motivation decreases after 5 months of chronic consumption of 48% ethanol solution in a dose of 4 g/kg; in animals with high alcohol motivation serotonin content decreases only in the hypothalamus. Under chronic alcoholization for 1 and 12 months no considerable changes were found in serotonin level of the studied tissues. 60 min after intraperitoneal administration of 20% ethanol solution in a dose of 3 g/kg in intact animals there occurs an increase of serotonin content in the brain hemispheres and heart and its decrease in the hypothalamus; in rat with low alcohol motivation after taking ethanol for 5 months this administration evokes a decrease of serotonin content in the hypothalamus and truncus cerebri; in rats with high alcohol motivation--its decrease in the hypothalamus. Excretion of 5-oxyindoleacetic acid with urine decreases 10 months after alcohol intoxication. When rats were not given ethanol after its chronic taking for 3 months serotonin oxidation was intensified for the first day, which was not observed after 7-month alcoholization of animals.     

Role of Zinc in the Regulation of Autophagy During Ethanol Exposure in Human Hepatoma Cells

Faulty autophagy has been linked to various diseases including neurodegenerative disorders, diabetes, and cancer. Increasing evidence support the notion that activation of autophagy protects against ethanol-induced steatosis and liver injury. Herein, we investigated the role of zinc in autophagy in human hepatoma cells VL-17A exposed or not to ethanol. LC3II/LC3I ratio, p62, and Beclin-1 expression and autophagosomes number were determined in cells incubated in medium containing various concentrations of zinc with or without ethanol. In addition, labile zinc and mRNA expression of metallothionein and the zinc transporters SLC39A8, SLC39A14, and SLC30A10 were evaluated in cells exposed to ethanol and the autophagy inhibitor 3-methyladenine. Zinc depletion caused a significant suppression of autophagy in cells. Conversely, zinc addition to medium stimulated autophagy in cells. Moreover, cotreatment with ethanol and excess zinc (40 μM) had an additive effect on the induction of autophagy. 3-methyadenine treatment decreased labile zinc, but this effect was more pronounced in cells exposed to ethanol. Lastly, ethanol and 3-methyladenine caused significant changes in the expression of metallothionein and zinc transporters. The results from this study support the hypothesis that zinc is critical for autophagy under basal conditions and during ethanol exposure.     

Level of delta sleep-inducing peptide (DSIP) in the brain of rats with different alcoholic motivation

Radioimmunoassay was used to measure the content of delta-sleep-inducing peptide (DSIP) in random-bred albino rats divided into groups according to the duration of ethanol anesthesia and the levels of 15% ethanol consumption under free-choice conditions. The concentration of the neuropeptide was assayed in intact brain, in the cortex of large hemispheres, medulla oblongata, thalamus and striatum. The short-sleeping rats manifested a statistically significant lowering of the DSIP content in intact brain homogenates, in the cortex of large hemispheres and striatum. On the contrary, thirty minutes after a single intraperitoneal injection of ethanol in a dose of 1 g/kg the DSIP content in the medulla oblongata, thalamus and striatum was found to be increased. The raising of the ethanol dose up to 2.5 and 4.5 g/kg was followed by a less significant increase in the neuropeptide content. Prolonged chronic alcoholization under free-choice conditions led after 12 months to the reduced DSIP content in the medulla oblongata, thalamus and striatum. The importance of DSIP for the pathogenesis of experimental alcoholism using rats with different levels of alcoholic motivation is discussed.     

Interaction of nutrition and binge ethanol treatment on brain damage and withdrawal

To determine if nutrition plays a role in ethanol withdrawal and alcohol-induced brain damage, the effects of a 4-day ethanol binge treatment using ethanol in a nutritionally complete liquid diet compared to ethanol mixed with water were studied. The nutritionally complete diet group (ETOH-diet) received a complete diet of sugars, proteins and fats with vitamins and minerals with approximately 53% of calories from ethanol while the nutritionally deprived group (ETOH-H2O) received 100% of calories from ethanol. No difference in withdrawal behavior was found between the ETOH-diet and ETOH-H2O groups during the 72-hour period studied. In addition, no difference was seen for serum levels of magnesium and zinc taken at last dose or following 72 h of withdrawal. Serum alanine aminotransferase (ALT) and ammonia were increased in both groups with ETOH-diet showing a greater increase in ALT than ETOH-H2O. Both groups showed damage in the olfactory bulb, perirhinal, agranular insular, piriform and lateral entorhinal cortical areas as well as hippocampal dentate gyrus and CA-3. Interestingly, the ETOH-diet group displayed more damage at last dose in the posterior dentate and CA-3 of hippocampus than did the ETOH-H2O group. This study suggests that nutritional components and total caloric intake do not effect behavior during ethanol withdrawal and that a nutritionally complete diet may increase ethanol-induced brain damage.