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1.
Perkinsus marinus, a protozoan parasite of the eastern oyster, Crassostrea virginica, causes high mortality in its host along the Atlantic and Gulf coasts of North America. P. marinus meronts cultured in vitro in medium containing complete lipid supplement (cod liver oil, cholesterol and alpha tocopherol acetate in detergent) are able to synthesize a wide variety of lipids, yet cultures cannot be maintained in lipid-free medium. To determine P. marinus lipid requirements meronts were inoculated into media containing different combinations of lipid components in detergent. Treatments included complete lipid supplement (positive control), detergent only (negative control), cholesterol in detergent, alpha tocopherol acetate in detergent and cholesterol+alpha tocopherol acetate in detergent. Meronts proliferated in the positive control medium and media containing cholesterol or cholesterol+alpha tocopherol acetate, but failed to proliferate in the negative control medium and the medium containing just alpha tocopherol acetate. Gas chromatography analysis of P. marinus meronts grown in medium with added (13)C sodium acetate (0.5 mg mL(-1)) revealed the presence of fatty acids containing (13)C, but the only sterol present was cholesterol containing no (13)C. These results suggest that P. marinus cannot synthesize sterols and must sequester them from its host.  相似文献   

2.

Background

Lycopene is the main carotenoid in tomatoes, where it is found in high concentrations. Strong epidemiological evidence suggests that lycopene may provide protection against cardiovascular diseases. We therefore studied the effects of lycopene on diet-induced increase in serum lipid levels and the initiation of atherosclerosis in New Zealand White (NZW) rabbits.

Methodology/Principal Findings

The animals, divided into four groups of 9 animals each, were fed either a standard diet, a high-cholesterol diet containing 0.5% cholesterol, a high-cholesterol diet containing placebo beadlets, or a high-cholesterol diet plus 5 mg/kg body weight/day of lycopene (in the form of lycopene beadlets), for a period of 4 weeks. We found significantly elevated lycopene plasma levels in the animal group treated with lycopene beadlets. Compared to the high-cholesterol and the placebo group, this was associated with a significant reduction of 50% in total cholesterol and LDL cholesterol serum levels in the lycopene group. The amount of cholesteryl ester in the aorta was significantly decreased by lycopene. However, we did not observe a significant decrease in the extent of aortic surface lipid accumulation in the lycopene group. In addition, no differences in the intima-media thickness among groups were observed. Endothelial-dependent and endothelial-independent vasodilation in isolated rabbit aortic and carotid rings did not differ among any of the animal groups.

Conclusions

Lycopene supplementation for 4 weeks increased lycopene plasma levels in the animals. Although we found strongly reduced total and LDL cholesterol serum levels as well as significantly lower amounts of cholesteryl ester in the aortae in the lycopene-treated group, no significant differences in initial lesions in the aortae were detected.  相似文献   

3.
Serum lipid concentrations were determined in rats treated with PGF2 alpha, PGE1, and controls. Administration of PGF2 alpha in rats influenced only the HDL lipid composition. HDL-cholesterol decreased while HDL-triglycerides increased. No significant difference was observed in the levels of serum total cholesterol, triglycerides, and phospholipids between animals treated with PGF2 alpha and controls. Reduced concentrations of serum lipid levels and especially of HDL-cholesterol, HDL-triglycerides, and HDL-phospholipids were found in the rats treated with PGE1. These results suggest that PGF2 alpha and PGE1 could modify serum lipid levels influencing lipoprotein metabolism.  相似文献   

4.
Conjugated linoleic acid (CLA) refers to a mixture of naturally occurring positional and geometric isomers of linoleic acid that exist in dairy products and meat. The aim of the present work was to study the effects of c-9,t-11 and t-10,c-12 CLA isomers on body fat accumulation and serum lipids in hamsters fed an atherogenic diet. Hamsters were divided in four groups: one group was fed a chow diet (control) and the other three groups were given semi-purified atherogenic diets with 0.5% linoleic acid (LA), c-9,t-11 or t-10,c-12 CLA. Body weight and food intake were measured daily. After 6 weeks, adipose tissues from different anatomical locations and liver were dissected and weighed. Serum glucose, total cholesterol, HDL-c, LDL-c and triacylglycerol levels, as well as total and free cholesterol, triacylglycerol and phospholipid content in liver were determined by enzymatic methods. No differences in either energy intake or final body weight were found. The addition of t-10,c-12 CLA reduced fat accumulation and led to lower serum cholesterol, as compared with LA group. Nevertheless the level remained higher than in the control animals. The reduction in serum cholesterol was limited to LDL-c. This isomer also reduced triacylglycerol content in liver but did not modify serum triacylglycerol level. In summary, the present study demonstrates that t-10,c-12 CLA is the biologically active agent when anti-obesity and hypocholesterolaemic properties of CLA are considered. In contrast, the isomer c-9,t-11 has no effect on lipid metabolism in hamsters.  相似文献   

5.
The purpose of the study was to assess the influence of dietary iron content on lipid and carbohydrate metabolism and on zinc and copper status in rats fed with a diet high in fat, fructose, and salt. Wistar rats were fed with diets high in fat, fructose, and salt, containing differing amounts of iron, namely, deficit, normal, and high levels. After 6 weeks, the animals were weighed and killed. The liver, heart, and pancreas were collected, as were blood samples. The total cholesterol, triglycerides, fasting glucose, and insulin levels in the serum were measured. The iron, zinc, and copper concentrations in tissues and serum were determined. It was found that in rats fed with the iron-deficit diet, cholesterol and glucose profiles improved. Both deficit and excess iron in the diet decreased insulin concentration in rats and disturbed iron, zinc, and copper status. High-iron level in the diet decreased the relative mass of the pancreas. In conclusion, the decrease in serum insulin concentration observed in rats fed with the modified diet high in iron was associated with iron and copper status disorders, and also, with a relatively diminished pancreas mass. A deficit of iron in the diet improved lipid and carbohydrate metabolism in rats.  相似文献   

6.
The incorporation of radioactive alpha tocopherol by various brain regions of wild type and apolipoprotein E (apoE)-deficient mice was investigated. Labeled tocopherol was injected into the lateral cerebral ventricles of 11 weeks old, male mice. Radioactive cholesterol injected simultaneously was used as an internal standard to account for experimental variability. Most areas of the brain of apoE-deficient mice took up less of alpha tocopherol per mg of protein than wild type animals. However, specific activity of alpha tocopherol was higher in cerebellum, pons, hypothalamus, midbrain and cerebral cortex in apoE-deficient brains than the wild type. This could be due to (a) the lower levels of alpha tocopherol in apoE-deficient brain and (b) reductions in the clearance and transport of tocopherol (possibly mediated by apoE). Tocopherol uptake by hippocampus was unusual since it was lower in apoE deficiency whether the data were expressed as specific activity or per mg of protein. Nearly all of the injected alpha tocopherol remained unchanged in the brains of both apoE-deficient and wild type animals suggesting low turnover. Overall, the current data reinforce the hypothesis that apoE is a key protein involved with the transport and/or retention of alpha tocopherol in brain.  相似文献   

7.
Dairy products are important sources of dietary fat in India. Anhydrous milk fat, viz., ghee, is consumed as such in the diet and also is used for frying the dishes. Ghee contains high levels of saturated fatty acids and cholesterol, which are considered risk factors for cardiovascular diseases. In the present study, ghee, at levels ranging from 0.25 to 10%, was included in a nutritionally balanced AIN-76 diet fed to Wistar rats for a period of 8 weeks. The serum lipid profiles of these animals showed a dose dependent decrease in total cholesterol, low density lipoproteins and very low density lipoproteins cholesterol, and triglyceride levels when ghee was present at levels greater than 2.5% in the diet. Liver cholesterol and triglycerides also were decreased in these animals. When ghee was included as a sole source of fat at a 10% level, polyunsaturated fatty acids in the serum and liver lipids were reduced significantly. Similar results were observed when ghee was subjected to a higher temperature (120 degrees C) to generate cholesterol oxidation products and fed to the animals. Although cholesterol oxidation products were not accumulated in serum, significant amounts were accumulated in liver only when ghee was fed as a sole source of fat at a 10% level. This study revealed that the consumption of ghee up to a 10% level in the diet altered blood lipid profiles in such a manner as not to elevate the risk factors for cardiovascular diseases.  相似文献   

8.
The serum lipid composition and the fatty-acid profiles of the major lipid fraction (triglycerides, esterified cholesterol, and phospholipid) of liver and serum were examined 6 weeks after both 50% and 75% distal small bowel resection (DSBR). Total serum lipid content did not modify after DSBR. Esterified cholesterol and phospholipid levels of the serum did not significantly change after the operation. However, a significant increase in both free cholesterol and triglyceride levels was observed after DSBR. Different fatty acid changes in the liver and serum lipid fractions were found after DSBR, with the greatest differences in the hepatic esterified cholesterol fraction. These results suggest that DSBR affects both the lipid composition and the fatty acid composition of major lipid fraction of liver and serum.  相似文献   

9.
This study was conducted to investigate the effects of increasing levels of alfalfa meal in the diet of laying quails on egg production, feed consumption, feed efficiency, egg quality, egg yolk cholesterol and selected serum parameters. In this study, 192, 10-week old quails (Coturnix coturnix japonica) were evenly distributed to four groups with four replicates of 12 quails each. The control group was fed a basal diet containing 0% alfalfa meal and the remaining groups received 3, 6 or 9% alfalfa meal for 12 weeks. Live weight, feed consumption, and egg production were recorded and feed efficiency were calculated. Eggs were examined for interior and exterior quality and egg yolk cholesterol content. At the end of the experiment, blood samples were collected and sera were analysed for serum Ca, inorganic P (P(i)), Mg, triglycerides and total cholesterol. Any level of alfalfa meal had no effect on live weight, egg production, feed consumption, feed efficiency, egg weight, and egg yolk index. Six percent and 9% alfalfa meal increased specific gravity of whole egg and eggshell thickness as well as serum P(i) levels. Nine percent alfalfa meal reduced serum triglycerides, total cholesterol levels and egg yolk cholesterol content. The results of this experiment indicated that addition of 9% alfalfa meal into the laying quail diet may improve eggshell quality and reduced serum triglycerides and serum and egg yolk cholesterol without any adverse effect on performance.  相似文献   

10.
It has been shown that the lowest level of total lipids, cholesterol, triacylglycerols and products of lipid peroxidation of blood and liver, as a rule, is specific to adult rats. These characteristics are significantly higher for old and young animals. At the same time, the level of glutathione and alphatocopherols in adults' liver is much higher than in young and old rats. It suggests the lower level of processes of lipid peroxidation in adult mature rats. The relative high level of products of lipid peroxidation and low content of alpha-tocopherols in old rats' liver (against the background of higher activity and glutamineperoxidase, and glutathionereductase than in adults) suggests tocopherol deficiency in old animals. High content of total lipids, cholesterol and cholesterol entering into the composition of lipoprotein of different density, triacylglycerols, diene conjugates and malonic dialdehide, activity of glutathione-dependent enzymes of antioxidant defence in young animals as compared with these levels in adult rats seems to be associated with agerelated hypercholesterolemia and intensive plastic changes of a growing organism.  相似文献   

11.
The effect of taurine on the serum and liver cholesterol and triglyceride levels was studied in rats fed cholesterol plus cholic acid. Four groups of 4 weeks old rats were fed control diet, hypercholesterolemic diet (HCD), HCD + 1% taurine or HCD + 2% taurine for 8 weeks. Addition of taurine in HCD diet showed a significant reduction not only in serum total cholesterol and triglyceride levels but also in liver total cholesterol, lipid and triglyceride contents compared to the animals fed HCD alone. Histological examination of organs of these animals showed severe fatty vacuolation in livers and signet ring type vacuolation in kidneys of rats fed HCD. Taurine showed ameliorating effect on these abnormalities. The animals fed taurine in HCD also showed increased bile and sterol excretion in faeces compared to rats fed HCD alone. Taurine showed significant hypocholesterolemia in rats probably by enhancing the catabolism of cholesterol and reducing the absorption of dietary cholesterol.  相似文献   

12.
The data are provided on the content of lipid and lipoproteins in the blood of young and old rabbits during long-term immunization with homologous heart antigen (once a week for 2.5 months). Two weeks after the beginning of the experiment the blood of immunized animals showed cardiac antibodies whose content rose, especially in young animals, in the course of the experiment. The content of immune complexes circulating in the blood also increased, with this increase being more pronounced in old rabbits. During immunization, the blood levels of lipoproteins total cholesterol, and triacylglycerins in old animals increased earlier and more intensely.  相似文献   

13.
The objective of this study was to determine whether a grape seed procyanidin extract (GSPE) exerts a triglyceride-lowering effect in a hyperlipidemic state using the fructose-fed rat model and to elucidate the underlying molecular mechanisms. Rats were fed either a starch control diet or a diet containing 65% fructose for 8 weeks to induce hypertriglyceridemia. During the 9th week of the study, rats were maintained on their respective diet and administered vehicle or GSPE via oral gavage for 7 days. Fructose increased serum triglyceride levels by 171% after 9 weeks, compared to control, while GSPE administration attenuated this effect, resulting in a 41% decrease. GSPE inhibited hepatic lipogenesis via down-regulation of sterol regulatory element binding protein 1c and stearoyl-CoA desaturase 1 in the fructose-fed animals. GSPE increased fecal bile acid and total lipid excretion, decreased serum bile acid levels and increased the expression of genes involved in cholesterol synthesis. However, bile acid biosynthetic gene expression was not increased in the presence of GSPE and fructose. Serum cholesterol levels remained constant, while hepatic cholesterol levels decreased. GSPE did not modulate expression of genes responsible for esterification or biliary export of the newly synthesized cholesterol, but did increase fecal cholesterol excretion, suggesting that in the presence of GSPE and fructose, the liver may secrete more free cholesterol into the plasma which may then be shunted to the proximal small intestine for direct basolateral to apical secretion and subsequent fecal excretion. Our results demonstrate that GSPE effectively lowers serum triglyceride levels in fructose-fed rats after one week administration. This study provides novel insight into the mechanistic actions of GSPE in treating hypertriglyceridemia and demonstrates that it targets hepatic de novo lipogenesis, bile acid homeostasis and non-biliary cholesterol excretion as important mechanisms for reducing hypertriglyceridemia and hepatic lipid accumulation in the presence of fructose.  相似文献   

14.
目的:观察左旋多沙唑嗪(-)DOX、右旋多沙唑嗪(+)DOX和消旋多沙唑嗪(±)DOX对高血脂家兔血脂水平及动物死亡率的影响。方法:取普通级雄性新西兰大耳白兔,给予高脂饮食4周后,血清TC小于10mmol/L的8只家兔为普通饮食组,饲以标准饲料。血清TC大于10mmol/L的40只家兔随机分为4组(n=10):高脂模型组、高脂模型+(-)DOX组、高脂模型+(+)DOX组以及高脂模型+(±)DOX组。普通饮食组和高脂模型组家兔腹腔注射无菌双蒸水;其他3组家兔分别腹腔注射(-)DOX、(+)DOX和(±)DOX,连续9周。分析药物对兔血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)的影响。结果:饲以高脂饮食13周时模型组家兔死亡率达40%,远远高于普通饮食组家兔(10%),亦明显高于(±)DOX和(-)DOX处理组。模型组家兔随高脂饲养的时间延长,血清LDL-C水平进一步显著升高(P0.05和P0.01);而各药物处理组动物的血清LDL-C水平未显著升高(P0.05)。结论:(-)DOX和(±)DOX可提高高脂饮食家兔的生存率,并对高血脂家兔的血清LDL-C紊乱具有轻度的改善作用;该作用可能不是其提高高脂饮食家兔生存率的主要作用机制。  相似文献   

15.
This study was conducted to investigate the effects of increasing levels of alfalfa meal in the diet of laying quails on egg production, feed consumption, feed efficiency, egg quality, egg yolk cholesterol and selected serum parameters. In this study, 192, 10-week old quails (Coturnix coturnix japonica) were evenly distributed to four groups with four replicates of 12 quails each. The control group was fed a basal diet containing 0% alfalfa meal and the remaining groups received 3, 6 or 9% alfalfa meal for 12 weeks. Live weight, feed consumption, and egg production were recorded and feed efficiency were calculated. Eggs were examined for interior and exterior quality and egg yolk cholesterol content. At the end of the experiment, blood samples were collected and sera were analysed for serum Ca, inorganic P (Pi), Mg, triglycerides and total cholesterol. Any level of alfalfa meal had no effect on live weight, egg production, feed consumption, feed efficiency, egg weight, and egg yolk index. Six percent and 9% alfalfa meal increased specific gravity of whole egg and eggshell thickness as well as serum Pi levels. Nine percent alfalfa meal reduced serum triglycerides, total cholesterol levels and egg yolk cholesterol content. The results of this experiment indicated that addition of 9% alfalfa meal into the laying quail diet may improve eggshell quality and reduced serum triglycerides and serum and egg yolk cholesterol without any adverse effect on performance.  相似文献   

16.
OBJECTIVES: To determine the extent to which plasma antioxidant concentrations in people with habitual low intake of fruit and vegetables respond to increased intakes of these foods. To examine whether advice to increase fruit and vegetables will result in reduction of concentrations of total and low density lipoprotein cholesterol. DESIGN: Randomised controlled trial in which intervention and control groups were followed up for eight weeks. The intervention group was asked to consume eight servings of fruit and vegetables a day. SETTING: Dunedin, New Zealand. SUBJECTS: Eighty seven subjects with normal lipid concentrations who ate three or fewer servings of fruit and vegetables daily. MAIN OUTCOME MEASURES: Plasma concentrations of vitamin C, retinol, alpha and beta carotene, alpha tocopherol, lipids, and lipoproteins. Dietary intake assessed with diet records over four days. RESULTS: The mean plasma vitamin C, alpha carotene, and beta carotene concentrations increased in parallel with increased dietary intake of fruit and vegetables in the intervention group. Concentrations of retinol, alpha tocopherol, lipids, and lipoproteins remained unchanged despite some increase in dietary vitamin E and a small reduction in saturated fat intake. CONCLUSIONS: Following a recommendation to increase fruit and vegetable consumption produces change in plasma concentrations of vitamin C, alpha carotene, and beta carotene likely to reduce incidence of cancer. More specific dietary advice to modify fat intake may be necessary to reduce the risk of cardiovascular disease mediated by lipoprotein and vitamin E.  相似文献   

17.
The manufacture of enveloped virus, particularly retroviral (RV) and lentiviral (LV) vectors, faces the challenge of low titers that are aggravated under serum deprivation culture conditions. Also, the scarce knowledge on the biochemical pathways related with virus production is still limiting the design of rational strategies for improved production yields. This work describes the adaptation to serum deprivation of two human RV packaging cell lines, 293 FLEX and Te Fly and its effects on lipid biosynthetic pathways and infectious vector production. Total lipid content as well as cellular cholesterol were quantified and lipid biosynthesis was assessed by (13)C-NMR spectroscopy; changes in gene expression of lipid biosynthetic enzymes were also evaluated. The effects of adaptation to serum deprivation in lipid biosynthesis were cell line specific and directly correlated with infectious virus titers: 293 FLEX cells faced severe lipid starvation-up to 50% reduction in total lipid content-along with a 68-fold reduction in infectious vector titers; contrarily, Te Fly cells were able to maintain identical levels of total lipid content by rising de novo lipid biosynthesis, particularly for cholesterol-50-fold increase-with the consequent recovery of infectious vector productivities. Gene expression analysis of lipid biosynthetic enzymes further confirmed cholesterol production pathway to be prominently up-regulated under serum deprivation conditions for Te Fly cells, providing a genotype-phenotype validation for enhanced cholesterol synthesis. These results highlight lipid metabolism dynamics and the ability to activate lipid biosynthesis under serum deprivation as an important feature for high retroviral titers. Mechanisms underlying virus production and its relationship with lipid biosynthesis, with special focus on cholesterol, are discussed as potential targets for cellular metabolic engineering.  相似文献   

18.
Developing atherosclerotic lesions in hypercholesterolemic rabbits are depleted in zinc, while iron accumulates. This study examined the influence of zinc supplementation on the development of atherosclerosis and used isotope dilution gas chromatography-mass spectrometry techniques to measure biomarkers of oxidative lipid damage in atherosclerotic rabbit aorta. Our previous method for F(2)-isoprostane measurement was adapted to include the quantitation of cholesterol oxidation products in the same sample. Two groups of New Zealand white rabbits were fed a high cholesterol (1% w/w) diet and one group was also supplemented with zinc (1 g/kg) for 8 weeks. Controls were fed a normal diet. Zinc supplementation did not significantly alter the increase in total plasma cholesterol levels observed in animals fed high cholesterol. However, in cholesterol-fed animals zinc supplementation significantly reduced the accumulation of total cholesterol levels in aorta which was accompanied by a significant reduction in average aortic lesion cross-sectional areas of the animals. Elevated levels of cholesterol oxidation products (5,6-alpha and beta cholesterol epoxides, 7beta-hydroxycholesterol, 7-ketocholesterol) in aorta and total F(2)-isoprostanes in plasma and aorta of rabbits fed a cholesterol diet were significantly decreased by zinc supplementation. Our data indicate that zinc has an antiatherogenic effect, possibly due to a reduction in iron-catalyzed free radical reactions.  相似文献   

19.
Adipophilin是细胞内脂质聚集和与脂质聚集有关疾病的标志物 ,巨噬细胞源性泡沫细胞的形成是动脉粥样硬化性疾病发生的重要环节 .为了探讨adipophilin在动脉粥样硬化性疾病的作用 ,通过高胆固醇饲料喂养新西兰白兔 12周 ,复制动脉粥样硬化疾病模型 ,同时测定血脂的变化和动脉壁胆固醇 ,使用HE染色、苏丹Ⅳ染色观察动脉粥样硬化病变的形成 ,使用免疫组织化学的方法观察动脉粥样硬化病变处和动物肝脏中adipophilin的表达 .结果发现 ,高胆固醇饲料喂养组血清总胆固醇、低密度脂蛋白胆固醇和动脉壁胆固醇明显增高 ,动脉粥样硬化病变面积增加到 (40 0 6± 7 2 9) % ,动脉粥样硬化病变处adipophilin表达呈阳性 ;而adipophilin在肝脏中的表达无论是高胆固醇饲料喂养组或对照组均为阴性 .使用80mg/L OxLDL与小鼠腹膜巨噬细胞共孵育 ,复制脂质负荷细胞 ,然后把构建的 1mmol/Ladipophilin反义寡核苷酸与该细胞共孵育 .结果发现 ,使用油红O染色观察的细胞内脂滴明显减少 ,生化测定细胞内胆固醇酯显著降低 ,与对照组相比 ,差别有显著性 .说明adipophilin与动脉粥样硬化病变有密切的关系 ,控制adipophilin的表达能够减少巨噬细胞细胞内胆固醇酯的聚集  相似文献   

20.
The 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) is the rate-limiting enzyme in the biosynthesis of cholesterol. We have studied the role of the HMGCR gene in pig lipid metabolism by means of expression and structural analysis. We describe here the complete coding region of this gene in pigs and report two synonymous single nucleotide polymorphisms in the coding region. We have, additionally, studied the association of one of these polymorphisms (HMGCR:c.807A>C) with several lipid deposition- and cholesterol-related traits in a half-sib population generated from a commercial Duroc line, showing in some families a positive relationship of HMGCR:c.807A allele with serum low-density lipoprotein (LDL)-bound cholesterol and triglyceride levels, and also with intramuscular fat (IMF) content of gluteus medius muscle. We have also assessed the expression levels in muscle and in liver from 68 Duroc individuals corresponding to the most extreme animals for the analysed traits. Liver HMGCR expression correlated negatively with the serum high-density lipoprotein (HDL) levels, carcass lean percentage and stearic acid content, while muscle expression correlated also negatively with the carcass lean percentage, stearic and linoleic acids content, but showed a positive correlation with the serum lipid cholesterol (HDL, LDL and total cholesterol), IMF and muscle oleic and palmitic fatty acid content. With this information, we have performed an association analysis of expression data with lipid metabolism phenotypic levels and the HMGCR genotype. The results indicate that HMGCR expression levels in muscle are different in the two groups of pigs with extreme values for fat deposition and total cholesterol levels, and also between animals with the different HMGCR genotypes.  相似文献   

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