维生素E对乙醇性肝损伤大鼠肝线粒体SOD和MDA的影响

目的:研究维生素E在乙醇性肝损伤肝组织亚细胞水平上的作用。方法:采用乙醇性肝损伤大鼠模型,测定乙醇灌胃及其VitE处理后肝线粒体SOD、MDA。结果:乙醇灌胃后肝线粒体SOD下降,而MDA上升;维生素E处理后SOD明显上升,MDA下降。结论:VitE可使乙醇性肝损伤大鼠肝线粒体SOD、MDA趋向正常,有抗氧化作用。     

VE、VC对大鼠肝、心组织中谷胱甘肽过氧化物酶、超氧化物歧化酶和过氧化脂质的影响

本实验研究选用14个月龄Wistar大白鼠,研究了VE、VC单独摄入与二者联合摄入后对谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)和过氧化脂质(LPO)的影响。结果表明,无论单独饲喂VE、VC或二者联合使用,肝LPO均低于对照组,差异非常显著。大剂量VC降低LPO的作用明显大于VE组。从GSH-Px和SOD的变化来看,VC具有明显提高GSH-Px和SOD活性的作用,与降低LPO的作用一致。     

Effect of Chronic Ethanol Feeding on Hepatic and Extrahepatic Distribution of Vitamin E in Rats

The effect of chronic ethanol feeding on the status of alpha- and gamma-tocopherol in plasma, liver, lung, and testes of Sprague-Dawley rats was characterized. Rats were pair-fed liquid diets containing 36% of total calories either as ethanol or isocaloric carbohydrates. After 3 weeks, ethanol ingestion resulted in a significant (p less than or equal to 0.05) increase in liver weight and induced fatty liver without affecting total body weight. Ethanol feeding did not affect the plasma concentration of alpha-tocopherol but doubled that of gamma-tocopherol. When expressed per milligram of tissue, liver alpha-tocopherol did not vary with ethanol ingestion, whereas gamma-tocopherol concentration increased 2.5 times that of control animals. However, the concentration of alpha-tocopherol expressed per milligram of total lipids was significantly (p less than or equal to 0.01) decreased in the liver with ethanol feeding. In contrast to the liver, ethanol feeding significantly increased alpha- and gamma-tocopherol levels per milligram of total lipids in the testes. The concentration of gamma-tocopherol (but not alpha-tocopherol) per milligram of lung tissue and per total lung was significantly (p less than or equal to 0.05) increased with ethanol feeding. These data indicate that chronic ethanol ingestion significantly alters the distribution of alpha-tocopherol and gamma-tocopherol in hepatic and extrahepatic tissues of the rat.     

Hepatic, Metabolic and Toxic Effects of Ethanol: 1991 Update

Until two decades ago, dietary deficiencies were considered to be the only reason for alcoholics to develop liver disease. As the overall nutrition of the population improved, more emphasis was placed on secondary malnutrition and direct hepatotoxic effects of ethanol were established. Ethanol is hepatotoxic through redox changes produced by the NADH generated in its oxidation via the alcohol dehydrogenase pathway, which in turn affects the metabolism of lipids, carbohydrates, proteins, and purines. Ethanol is also oxidized in liver microsomes by an ethanol-inducible cytochrome P-450 (P-450IIE1) that contributes to ethanol metabolism and tolerance, and activates xenobiotics to toxic radicals thereby explaining increased vulnerability of the heavy drinker to industrial solvents, anesthetic agents, commonly prescribed drugs, over-the-counter analgesics, chemical carcinogens, and even nutritional factors such as vitamin A. In addition, ethanol depresses hepatic levels of vitamin A, even when administered with diets containing large amounts of the vitamin, reflecting, in part, accelerated microsomal degradation through newly discovered microsomal pathways of retinol metabolism, inducible by either ethanol or drug administration. The hepatic depletion of vitamin A is strikingly exacerbated when ethanol and other drugs were given together, mimicking a common clinical occurrence. Microsomal induction also results in increased production of acetaldehyde. Acetaldehyde, in turn, causes injury through the formation of protein adducts, resulting in antibody production, enzyme inactivation, decreased DNA repair, and alterations in microtubules, plasma membranes and mitochondria with a striking impairment of oxygen utilization. Acetaldehyde also causes glutathione depletion and lipid peroxidation, and stimulates hepatic collagen production by the vitamin A storing cells (lipocytes) and myofibroblasts.(ABSTRACT TRUNCATED AT 250 WORDS)     

Early Alcoholic Liver Injury: Formation of Protein Adducts with Acetaldehyde and Lipid Peroxidation Products, and Expression of CYP2E1 AND CYP3A

The formation of protein adducts with reactive aldehydes resulting from ethanol metabolism and lipid peroxidation has been suggested to play a role in the pathogenesis of alcoholic liver injury. To gain further insight on the contribution of such aldehydes in alcoholic liver disease, we have compared the appearance of acetaldehyde, malondialdehyde, and 4-hydroxynonenal adducts with the expression of cytochrome P-450IIE1, and cytochrome P-4503A enzymes in the liver of rats fed alcohol with a high-fat diet for 2 to 4 weeks according to the Tsukamoto-French procedure and in control rats (high-fat liquid diet or no treatment). Urine alcohol and serum aminotransferase levels were recorded, and the liver pathology was scored from 0 to 10 according to the presence of steatosis, inflammation, necrosis, and fibrosis. The ethanol treatment resulted in the accumulation of fat, mild necrosis and inflammation, and a mean liver pathology score of 3 (range: 1 to 5). Liver specimens from the ethanol-fed animals with early alcohol-induced liver injury were found to contain perivenular, hepatocellular acetaldehyde adducts. Malondialdehyde and 4-hydroxynonenal adducts were also present showing a more diffuse staining pattern with occasional sinusoidal reactions. In the control animals, a faint positive reaction for the hydroxynonenal adduct occurred in some of the animals fed the high fat diet, whereas no specific staining was observed in the livers from the animals receiving no treatment Expression of both CYP2E1 and CYP3A correlated with the amount of protein adducts in the liver of alcohol-treated rats. Distinct CVP2E1 -positive immunohistochemistry was seen in 3 of 7 of the ethanol-fed animals. In 5 of 7 of the ethanol-fed animals, the staining intensities for CYP3A markedly exceeded those obtained from the controls. The present findings indicate that acetaldehyde and lipid peroxidatjon-derived adducts are generated in the early phase of alcohol-induced liver disease. The formation of protein adducts appears to be accompanied by induction of both CVP2E1 and CVP3A.     

Protective Effect of Cornus mas Fruits Extract on Serum Biomarkers in CCl4-Induced Hepatotoxicity in Male Rats

Background:

Nowadays attention to use herbs such as cornelian cherry (Cornus mas) is increasing, which contains high levels of antioxidants and anthocyanins. Cornus mas fruits have been used for gastrointestinal and excretory disorders for many years in traditional medicine, also may improve liver and kidney functions, and have protective effects such as anti-allergic, antidiabetic, antibacterial, antimicrobial, antihistamine and antimalarial properties.

Objectives:

The aim of this study was to investigate protective effects of Cornus mas fruits extract on serum biomarkers in CCl₄-induced hepatotoxicity in male rats.

Materials and Methods:

Hepatotoxicity was induced by administration of carbon tetrachloride (1 mL/kg i.p.) in 1:1 dilution with olive oil. To evaluate the effect of Cornus mas fruits extract on disease progression, serum marker enzymes, serum total protein and albumin and liver lipid peroxidation were determined in CCl₄-induced hepatotoxicity.

Results:

Oral administration of Cornus mas fruits extract to rats for 14 days provided a significant (P < 0.05) hepatoprotection by decreasing elevated serum level of enzymes, total serum protein, albumin and liver lipid peroxidation content.

Conclusions:

Cornus mas fruit extract effect may be due to including some antioxidant components, which caused membrane stabilizing and normalization of fluctuated biochemical profiles induced by CCl₄ exposure. Our results validated the traditional use of Cornus mas in the treatment of liver disorders.     

Effects of Ethanol and Carbon Tetrachloride upon Vitamin A Status of Rats

The effects of ethanol and carbon tetrachloride (CCl4) upon tissue vitamin A, liver lipids, liver cytochrome P450 and hepatic morphology were investigated. It was anticipated that CCl4 treatment would have more severe effects upon vitamin A status because CCl4 provides greater hepatic injury than does ethanol. After a 2-week standardization feeding period, young male rats were divided into four groups. For 5 weeks one group of rats (n = 17) received ethanol in liquid diets (30% of calories) while another (n = 8) was exposed to CCl4 inhalation twice a week along with phenobarbital in the diet. All groups received the National Regulatory Commission recommended level for vitamin A. Comparison of ethanol and its pair-fed control group (n = 17) revealed: decreased hepatic vitamin A, no change in serum vitamin A, increased percentage of liver lipid, and cytochrome P450 with moderate fat accumulation in hepatocytes. Comparison of the CCl4-phenobarbital group with pair-fed controls (n = 8) showed: increased serum vitamin A, decreased hepatic vitamin A, increased cytochrome P450, marked hepatic fat accumulation, hepatic cell necrosis, and early cirrhosis. Thus, CCl4 (with phenobarbitol), which is a more potent hepatotoxin as evidenced by a more elevated cytochrome P450 and distorted liver morphology, not only reduced liver vitamin A, but also increased serum vitamin A. The extent of substrate and/or organ specificity remains to be elucidated.     

Vitamin E attenuates alcohol-induced aortic wall damage in rats

BackgroundIn this study the effect of chronic ethanol consumption on vascular wall abnormality via oxidative stress was examined. It was also intended to find out whether vitamin E inhibits the abnormality induced by ethanol in rat vascular wall.MethodsTwenty-four male wistar rats were divided into three groups, namely, control, ethanol (4.5 g/kgBW intragastrically), and vitamin E treated ethanolic groups(VETE) (300 mg interagastrically).ResultsAfter 6 weeks treatment of rats, the results revealed that along with a significant increase VSMC proliferation and aorta wall thickness with the increase in the level of Ox-LDL, protein carbonyl, as well as decrease total antioxidant capacity in animal that received ethanol compared to the control group. Significant amelioration of aorta wall changes, along restoration of the elevated level of Ox-LDL, protein carbonyl, lipid profile, and decreased level of total antioxidant capacity to that of controls were found in vitamin E-treated animals.ConclusionsThese findings strongly support the idea that heavy and chronic ethanol consumption initiate atherosclerosis by oxidative stress, and that these effects can be alleviated by vitamin E as an antioxidant.     

In Utero Ethanol Exposure Elicits Oxidative Stress in the Rat Fetus

Prior studies in our laboratory have shown that exposure of cultured fetal rat hepatocytes to ethanol (E) blocks epidermal growth factor-dependent replication and that this is paralleled by cell membrane damage, mitochondrial dysfunction, membrane lipid peroxidation (LP), and enhanced generation of reactive oxygen species. These measures of E-mediated oxidative stress (OS) were mitigated by treatment with antioxidants, and cell replication could be normalized by maintaining cell glutathione (GSH) pools. We have now extended these studies to an in vivo model. Rats were administered E (4 g/kg, po) at 12-hr intervals on days 17 and 18 of gestation and killed on day 19,1 hr following a final dose of E (a total of 5 doses). Fetal and maternal brain and liver were assayed for signs of OS. The 2-day in utero E exposure increased membrane LP in fetal brain as evidenced by increased malondialdehyde (MDA) levels from 1.76 ± 0.12 se (nMol/mg protein) to 2.00 ± 0.08 (p < 0.05) and conjugated dienes from 0.230 ± 0.006 se (OD₂₃₃/mg lipid) to 0.282 ± 0.006 (p < 0.05). In fetal liver, MDA levels increased from 2.39 ± 0.08 se (nMol/mg protein) to 2.87 ± 0.08 (p < 0.05), whereas dienes differed significantly only between ad libitum controls and the E and pair-fed control groups (p < 0.05). E decreased GSH levels in fetal brain by 19%, from 19.88 ± 0.72 to 16.13 ± 1.06 (nMol/mg protein) (p < 0.05). A10% decrease in GSH was seen in fetal liver (p < 0.05). GSH in maternal brain was decreased by 44% from 47.29 ± 3.38 to 26.60 ± 2.29 (p < 0.05). Other E-related increases in these OS measures were not observed in maternal organs. E did not decrease α-tocopherol levels in fetal and maternal brain or in fetal liver (p < 0.05), whereas maternal liver α-tocopherol content was reduced by 31% (p < 0.05) by E treatment. It is concluded that maternal E consumption can induce an OS in fetal tissues that may contribute to the fetotoxic effects of E.     

维生素C、E对氟中毒大鼠不同组织抗氧化酶活性影响的研究

目的探讨氟中毒大鼠肝、肾、脑组织抗氧化酶类及脂质过氧化物的变化以及维生素 C、E 单独和联合干预以及不同剂量干预对高氟状态下大鼠抗氧化酶活性及脂质过氧化物的影响。方法将120只 Wistar 大鼠随机分为9绀,饮水染氟建立氟中毒大鼠模型,并灌胃给予维生素 C 和/或维生素 E;9月后处死大鼠取肝、肾、腑组织测定超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氧酶(CAT)活性和脂质过氧化物丙二醛(MDA)含量。结果染氟组大鼠肝、肾、脑组织 MDA 含量显著增加,肝和腑绀织 SOD、GSH-Px 和 CAT 活性以及肾组织 GSH-Px 活性均显著降低(P<0.05),而肾组织 SOD、CAT 活性无明显变化;维生素 C、E 可不同程度地增强 SOD、GSH-Px 和 CAT 活性,降低 MDA 水平;联合干预维生素 C、E 可明显拮抗氟诱导的脂质过氧化作用,显著增强大鼠肝组织 SOD、GSH-Px 和 CAT活性;维生素 C 低制量干预对肾脏 SOD 和 CAT 以及脑 GSH-Px 和 CAT 具有明显的保护作用;维生素 E 高剂量干预显著增加脑 SOD 活性。结论维生素 C 和维生素 E 在一定剂量范围内可有效拮抗过量氟导敛的脂质过氧化作用,对氟中毒大鼠肝、肾、脑组织有明显的保护作用。     

Vitamin E prevents ethanol-induced inflammatory, hormonal, and cytotoxic changes in reproductive tissues

Ethanol causes decreased function of the hypothalamic–pituitary–gonadal (HPG) axis. Ethanol resulted in inflammatory changes in HPG manifested by increased concentrations of pro-inflammatory cytokines. Since, such cytokines have deleterious effects on functions of HPG, it seemed possible that ethanol’s suppressive action could be due, at least in part, to this inflammation. Since oxidative stress can cause inflammation, we have used the antioxidant vitamin E to test, whether reducing inflammation might protect reproductive functions from ethanol. Rats were fed an ethanol diet or pair fed identically without ethanol for a 3-week period. For the last 10 days, animals were given 30 IU/kg or 90 IU/kg or vehicle. Ethanol significantly increased hypothalamic, pituitary and testicular TNF-α and IL-6, all changes prevented by the higher dose of vitamin E. Also, ethanol induced changes in LHRH, LH, testosterone, and testicular germ cell apoptosis were similarly prevented by vitamin E. These data strikingly show that vitamin E protects the HPG from deleterious effects of ethanol and suggests that the mechanism of this protection might be both anti-inflammatory and antioxidant.     

Dietary Vitamin E Modulation of Cytokine Production by Splenocytes and Thymocytes from Alcohol-Fed Mice

As vitamin E enhances immune responses, it may reduce dietary ethanol (EtOH)-induced immune suppression, thereby favorably afffecting host disease resistance. The effects of dietary vitamin E at higher level in alcohol-fed female C57BL/6 mice was determined via in vitro cytokine production by splenocytes and thymocytes, and some other immune functions. A 15-fold increase of vitamin E (160IU/liter) in a liquid diet (National Council Research), with or without EtOH (4.5%, v/v), was fed to mice for 10 weeks. Vitamin E supplementation restored production of interleukin-2, -5, -6, -10, and inter-feron-γ by concanavalin A (Con A)-stimulated splenocytes and in terleukin-6 and tumor necrosis factor-a by lipopolysaccharide-stimulated splenocytes, which were suppressed by dietary EtOH. However, it had no effect on interleukin-4 secretion, which was also reduced by splenocytes from EtOH-fed mice. Vitamin E supplementation also restored EtOH-suppressed, mitogen-induced splenocyte proliferation, but not thymocyte proliferation, although it slightly increased production of immunoglobulin A and G by lipopolysaccha-ride-stimulated splenocytes, which were suppressed by dietary EtOH. Dietary vitamin E, furthermore, significantly increased interleu-kin-2 and -6 secretion by Con A-stimulated thymocytes, which were suppressed by dietary EtOH, although it had no effect on interleukin- 4 and interferon-γ production by Con A-stimulated thymocytes from EtOH-fed mice. These data suggest that dietary vitamin E supple-mentation can modulate dysregulation of cytokines initiated by dietary EtOH and restore immune dysfunctions induced by EtOH ingestion.     

Effect of Chronic Ethanol on Apolipoprotein (Apo) E Synthesis and Glycosylation in Rats

We have previously shown in rats that chronic ethanol feeding significantly inhibits the incorporation of labeled leucine into Apo E secreted into the liver perfusate (p less than 0.01). Fish oil has been shown to counteract many of the adverse effects of ethanol. In order to explore whether this inhibitory effect of ethanol was due to the decreased synthesis and/or defective glycosylation of this glycoprotein, we have determined the effects of chronic ethanol and fish oil on the synthesis and glycosylation of Apo E in vivo. Four groups of male Wistar rats were pair-fed the following liquid diets for 8 weeks; (1) Ethanol Regular Fat, (2) Control Regular Fat, (3) Ethanol Fish Oil, and (4) Control Fish Oil. At the end, the rats were intraportally injected with a single dose of [U-14C]leucine (0.2 microCi/g body weight) and/or [2-3H]mannose (1 microCi/g body weight) and killed after 30 min. The incorporation of the labeled precursors into the immunoprecipitable Apo E was measured in the liver and its microsomal and Golgi fractions. The results showed marked decreases in mannose incorporation into total glycoproteins and specifically of Apo E in whole liver, microsomal, and Golgi fractions under ethanol treatment. In contrast, the leucine incorporation into liver Apo E increased 11% (p less than 0.048) by ethanol treatment. As a result, the [3H]mannose/[14C] leucine incorporation ratio also decreased 41% to 47% at the whole liver, microsomal, and Golgi fractions indicating a marked inhibition in glycosylation of Apo E in the ethanol group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of Vitamin E Deficiency on Inhibition of Liver Regeneration by Long-Term Administration of Alcohol

The effects of vitamin E (VE) deficiency on liver regeneration suppressed by long-term administration of alcohol were studied. Male rats were divided into two groups: the alcohol group and the control group. In addition, each group was subdivided into two groups according to the presence or not of VE. Altogether, four groups were provided: a group maintained on the VE-deficient alcohol diet (group EA), a group maintained on the VE-deficient control diet (group EC), a group maintained on the ordinary alcohol diet (group A), and a group maintained on the ordinary control diet (group C). After pair-feeding for 6 weeks, partial hepatectomy was performed to determine the ornithine decarboxylase (ODC) activity, polyamine levels, lipid peroxide levels, and DNA synthesis. DNA synthesis at 24 hr after partial hepatectomy was suppressed significantly in the alcohol administration group, regardless of the presence or not of VE. DNA synthesis at 48 hr after partial hepatectomy tended to show low values in group EA, compared with group A. As for the hepatic ODC activity, group EA showed the lowest value at 4 hr after partial hepatectomy. Of polyamines, the putrescine level in group EA at 4 hr after partial hepatectomy was significantly low, compared with the other three groups. The levels of spermidine and spermine decreased by long-term administration of alcohol, but the effect of VE deficiency was not found. The lipid peroxide level increased significantly in the VE-deficient diet administration group, but the effect of alcohol administration was not found. These results suggested that the decrease in putrescine after ODC suppression by VE deficiency in addition to the decrease in spermidine and spermine caused by long-term alcohol administration were concerned with suppression of DNA synthesis later.     

Changes in Microsomal Phospholipases and Arachidonic Acid in Experimental Alcoholic Liver Injury: Relationship to Cytochrome P-450 2E1 Induction and Conjugated Diene Formation

We evaluated the role of changes in microsomal phospholipases (A and C) and arachidonic acid in the intragastric rat feeding model. The experimental animals (male Wistar rats), divided into 4–5 rats/group, were fed the following diets: corn oil and ethanol and corn oil plus dextrose. One set of groups was killed after 2 weeks of feeding, and the second set was killed after 1 month. For each animal, microsomal analysis of cytochrome P-450 2E1 (CYP 2E1) and fatty acids was done. Fourteen animals had analyses of phospholipase C (PLC) and phospholipase A (PLA), and 10 animals had measurements of conjugated dienes. A significant correlation was obtained between the level of CYP 2E1 and the decrease in arachidonic acid (AA) from baseline levels ( r = 0.69, p < 0.01). The decrease in AA also correlated with the increase in conjugated dienes ( r = 0.70, p < 0.05). PLA and PLC activities were both significantly increased in the corn oil and ethanol groups. The activity of PLC correlated with the decline in AA ( r = 0.69, p < 0.01). The correlations noted between the decrease in microsomal AA and CYP 2E1 induction and conjugated diene formation suggest that these processes may be interlinked especially in regard to generation of lipid peroxides that may play a role in alcoholic liver injury.     

维生素E抗大鼠四氯化碳所致肝纤维化的实验研究

目的为探讨维生素Ｅ（ＶＥ）对肝纤维化的治疗作用。方法观察了ＶＥ对四氯化碳（ＣＣＩ４）诱导的肝纤维化大鼠肝功能，脯氨酸肽酶（ＰＬＤ）、透明质酸（ＨＡ）、丙二醛（ＭＤＡ）、超氧化物歧化酶（ＳＯＤ）及肝脏组织学的影响。同时没有正常对照、溶剂对照及空白对照组。结果维生素Ｅ治疗１０周后，上述生化指标除ＨＡ（３８７．５７±１２９．３９ｎｇ／ｍｌ）仍示达正常外，其余各指标均恢复正常，其中ＡＬＴ于第２周后、ＰＬＤ和ＭＤＡ于第４周后恢复。溶剂对照及空白对照组在第１０周时各指标虽有下降，仍高于ＶＥ治疗组（Ｐ＜０．０１，Ｐ＜０．０５）；光镜观察治疗组大鼠肝内网状纤维由粗大变纤细并有缩短和断裂，经真彩色图像系统分析与对照组比较差异有显著性（Ｐ＜０．０１）。结论ＶＥ治疗有助于实验性四氯化碳肝纤维化的恢复。     

Lipid peroxidation in lung of rat stressed by immobilization: Effects of vitamin E supplementation

This study was carried out to examine the possibility of initiation of lipid peroxidation in the lung of Wistar albino male rats stressed by immobilization. The effects of vitamin E supplementation were also investigated. We found that immobilization of rats with normal pulmonary content of vitamin E caused lipid peroxidation in the lung. Decrease of the lung content of unsaturated fatty acids and vitamin E was also established. The immobilization-induced changes of all of these parameters were significantly inhibited by vitamin E injection (100 mg/kg body weight) for 7 days. A possible sequence of events leading to the initiation of lipid peroxidation and lung cell membrane damage in rats stressed by immobilization is discussed. Offprint requests to: Stefan Ribarov, PhD     

硒和维生素E对实验性肝纤维化的协同保护作用

目的：观察硒(Se)和维生素E(Vit．E)单独应用和联合应用对肝纤维化的影响。方法：以40％ CCl4制备大鼠肝纤维化模型，分别以单纯和联合补充Se和Vit．E的形式，观察血清肝功能指标(ALT、AST、Glb)、肝纤维化指标(HA)、抗氧化指标(SOD)和肝脏组织学变化。结果：单纯补充Se或Vit．E能够降低大鼠血清ALT、AST和Glb的含量，减轻肝细胞变性及肝纤维化增生程度，对SOD活性无显著性影响，单纯补充Vit.E能降低HA水平。联合补充Se和Vit．E对以上指标均有明显改善，且能显著提高SOD活性。结论：Se和Vit．E联合应用优于单一应用，二者具有协同保护效应。     

低硒环境下蛋氨酸对大鼠体内维生素E,硒及脂质过氧化物含量的影响

用低硒、低蛋氨酸饲料喂养大鼠8周后发现大鼠血清、肝脏及心肌中脂质过氧化物含量显著升高,血清维生素E显著下降,而心肌硒含量却显著升高。实验结果表明,在低硒环境下如降低饲料中蛋氨酸水平将导致大鼠体内脂质过氧化反应加剧。     

Vitamin E status in normocholesterolemic and hypercholesterolemic diabetic patients

Summary The close relationship between vitamin E, lipid and prostaglandin metabolism stresses the need for an accurate definition of the status of vitamin E in a diabetic population. Plasma vitamin E and plasma lipids were determined in 34 type I and 21 type II normocholesterolemic and in 7 hypercholesterolemic diabetics. They were also measured in 62 age-and sex-matched controls, 34 normocholesterolemic controls for type I, 21 normocholesterolemic controls for type II and 7 hypercholesterolemic individuals. Plasma vitamin E levels were not significantly different in type I and type II diabetics as compared to their respective control groups. Vitamin E levels were significantly increased (p<0.001) in hypercholesterolemic individuals, both in diabetics and in non-diabetics. The vitamin E/cholesterol ratio in these subjects was, however, not different from that of normocholesterolemic. Plasma vitamin E was correlated with plasma lipids, especially with total and LDL-cholesterol (p<0.001). Since vitamin E is mainly transported by plasma lipoproteins, these strong correlations suggest that changes in plasma vitamin E should be considered as an epiphenomenon of altered plasma transport capacity.