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1.
Atherosclerosis in inbred mouse strains has been widely studied by using an atherogenic (Ath) diet containing cholesterol, cholic acid, and fat, but the effect of these components on gene expression has not been systematically examined. We employed DNA microarrays to interrogate gene expression levels in liver of C57BL/6J mice fed the following five diets: mouse chow, the Ath diet, or modified versions of the Ath diet in which either cholesterol, cholate, or fat were omitted. Dietary cholesterol and cholate produced discrete gene expression patterns. Cholesterol was required for induction of genes involved in acute inflammation, including three genes of the serum amyloid A family, three major histocompatibility class II antigen genes, and various cytokine-related genes. In contrast, cholate induced expression of genes involved in extracellular matrix deposition in hepatic fibrosis, including five collagen family members, collagen-interacting proteins, and connective tissue growth factor. The gene expression findings were confirmed by biochemical measurements showing that cholesterol was required for elevation of circulating serum amyloid A, and cholate was required for accumulation of collagen in the liver. The possibility that these gene expression changes are relevant to atherogenesis in C57BL/6J mice was supported by the observation that the closely related, yet atherosclerosis-resistant, C57BL/6ByJ strain was largely resistant to dietary induction of the inflammatory and fibrotic response genes. These results establish that cholesterol and cholate components of the Ath diet have distinct proatherogenic effects on gene expression and suggest a strategy to study the contribution of acute inflammatory response and fibrogenesis independently through dietary manipulation.  相似文献   

2.
Extracellular matrix remodelling plays an essential role in tissue engineering of load-bearing structures. The goal of this study is to model changes in collagen fibre content and orientation in soft connective tissues due to mechanical stimuli. A theory is presented describing the mechanical condition within the tissue and accounting for the effects of collagen fibre alignment and changes in fibre content. A fibre orientation tensor is defined to represent the continuous distribution of collagen fibre directions. A constitutive model is introduced to relate the fibre configuration to the macroscopic stress within the material. The constitutive model is extended with a structural parameter, the fibre volume fraction, to account for the amount of fibres present within the material. It is hypothesised that collagen fibre reorientation is induced by macroscopic deformations and the amount of collagen fibres is assumed to increase with the mean fibre stretch. The capabilities of the model are demonstrated by considering remodelling within a biaxially stretched cube. The model is then applied to analyse remodelling within a closed stented aortic heart valve. The computed preferred fibre orientation runs from commissure to commissure and resembles the fibre directions in the native aortic valve.  相似文献   

3.
The effects of chronic treatment of taurine on hypercholesterolemia and atherosclerosis were examined in C57BL/6J mice fed a high-fat diet containing 15% fat and 1.25% cholesterol. Taurine was dissolved in drinking water at 1% (w/v) and was given to mice ad libitum during 6 months-feeding of a high-fat diet. Hypercholesterolemia occurred and lipid accumulation on the aortic valve was evident. Taurine treatment lowered serum LDL + VLDL cholesterol by 44% in mice fed a high-fat diet, while it elevated serum HDL cholesterol by 25%. As a result, the atherogenic index, the ratio of HDL to LDL + VLDL was markedly improved. Cholesterol content in the liver also decreased by 19% with taurine. Similar tendencies were seen in mice fed regular chow, but the changes were not significant. The area of aortic lipid accumulation, which served as an index of atherosclerosis, was reduced by 20% with taurine. In the liver, taurine doubled the activity of cholesterol 7alpha-hydroxylase. These observations, together with prior findings, suggest that the cholesterol-lowering action of taurine may relate to the increased conversion of cholesterol to bile acids via stimulation of cholesterol 7a-hydroxylase activity. Thus, chronic treatment of high-fat mice with taurine improves the abnormal profile of the serum lipoproteins, and thereby retards the progression of atherosclerosis.  相似文献   

4.
An increase of total glycosaminoglycan content in aortic wall and liver as well as changes in the concentration of glycosaminoglycan fractions in aorta, skin, liver, and blood serum were found in white rats fed with atherogenic diet. Urinary excretion of glycosaminoglycans was increased in experimental animals.  相似文献   

5.
The aim of the study was to investigate the effect of two various atherogenic stimuli (vasopressin-induced hypertension or hypercholesterolemia) on the collagen and glycosaminoglycan (GAG) content in the internal or external part of both thoracic and abdominal aorta, which are differently susceptible to atherosclerosis. Experimental rabbits were divided into four groups: controls, animals injected with physiological saline or vasopressin at the dose of 1 IU/kg from the 1 st to the 25 th day of experiment, respectively. The animals from group 4 were maintained on food, containing 0.25% cholesterol. Only in the vasopressin-treated group, the systolic blood pressure was elevated from 110 mmHg at the beginning, to 166 mmHg at the end of the study. After 14 weeks the aorta was dissected into internal and external parts. GAG fractions were separated and estimated as uronic acids. Collagen was evaluated as the hydroxyproline content in the tissue. Augmented total GAG and heparan sulphate (HS) level, plus no changes in the collagen content were seen in the internal part of the thoracic aorta in rabbits with hypercholesterolemia or hypertension. In the hypertensive animals, the changes were extended to the external part of the aorta and, additionally, comprised the elevation of the chondroitin-4 sulphate (C-4S) content. The two atherogenic stimuli increased the collagen level with no elevation of the GAG content in the abdominal aorta. A convergent effect of the injury, caused by hypertension or hypercholesterolemia on the collagen, total GAG and HS content was shown in the respective parts of the rabbit aortas. The common GAG, increased in the thoracic aorta, stand for the HS, in both hypertensive and hypercholesterolemic rabbits. As the sensitivity to atherosclerosis development in different segments of the aorta varies, they express various responses of the connective tissue matrix to injuries, caused by hypertension or hypercholesterolemia.  相似文献   

6.
Hyperlipidemia is a major risk factor for developing atherosclerosis in humans, and epidemiological studies have correlated specific lipoprotein levels with cardiovascular disease risk. Murine models of atherosclerosis rely on the induction of hyperlipidemia for vascular lesions to form, but the pathogenic contributions attributed to different lipoprotein populations are not well defined. To address this issue, we analyzed over 300 LDL receptor (LDLR) deficient mice that have been fed a high-fat diet and for which a full lipoprotein profile and aortic root atherosclerosis values were assessed. Overall, aortic root atherosclerosis is best predicted by plasma VLDL cholesterol levels with less predictive value derived from either LDL or HDL cholesterol. Triglyceride levels are more atherogenic in female mice, especially immune competent females, and depletion of the adaptive immune system leads to a global reduction in plasma lipid levels and aortic root lesion size yet does not appear to alter the atherogenic potential of individual lipoprotein subspecies. In contrast, HDL-cholesterol is a better predictor of aortic root atherosclerosis in apoE-deficient mice. In summary, this large scale analysis of high-fat diet fed LDLR deficient mice highlight the relationship between different plasma lipid components, especially VLDL-cholesterol, and aortic root atherosclerosis.  相似文献   

7.
The synthesis and (or) release of endothelium-dependent relaxant factor released by acetylcholine is impaired in New Zealand white rabbits fed an atherogenic diet. Experiments were designed to investigate whether the synthesis and (or) release of the endothelium-dependent relaxant factor from rabbit aortas are restored after reversal from an atherogenic diet to a non-atherogenic diet. Atherosclerosis was induced by feeding a diet containing lipids and 2% cholesterol for 6 weeks. Rabbits were sacrificed after 6 weeks on the atherogenic diet and 36 weeks after return to a standard laboratory diet. Synthesis and (or) release of the factor from the thoracic aorta was assayed using a bioassay system. The relaxant responses produced in the assay tissue were impaired both in the acute stage and after 36 weeks on non-atherogenic food. This impaired relaxation is probably due to a persistent functional abnormality in the aortic endothelium resulting in the failure to synthesize and (or) release endothelium-dependent relaxation factor 36 weeks after induction of atherosclerosis.  相似文献   

8.
The factors underlying cardiovascular risk in patients with diabetes have not been clearly elucidated. Efforts to study this in mice have been hindered because the usual atherogenic diets that contain fat and cholesterol also lead to obesity and insulin resistance. We compared plasma glucose, insulin, and atherosclerotic lesion formation in LDL receptor knockout (Ldlr(-/-)) mice fed diets with varying fat and cholesterol content that induced similar lipoprotein profiles. Ldlr(-/-) mice fed a high-fat diet developed obesity, mild hyperglycemia, hyperinsulinemia, and hypertriglyceridemia. Quantitative and qualitative assessments of atherosclerosis were unchanged in diabetic Ldlr(-/-) mice fed a high-fat diet compared with lean nondiabetic control mice after 20 weeks of diet. Although one group of mice fed diets for 40 weeks had larger lesions at the aortic root, this was associated with a more atherogenic lipoprotein profile. The presence of a human aldose reductase transgene had no effect on atherosclerosis in fat-fed Ldlr(-/-) mice with mild diabetes. Our data suggest that when lipoprotein profiles are similar, addition of fat to a cholesterol-rich diet does not increase atherosclerotic lesion formation in Ldlr(-/-) mice.  相似文献   

9.
In the present study, Fourier‐transform infrared spectroscopy (FTIR) is investigated as a method to measure connective tissue components that are important for the quality of Atlantic cod filets (Gadus morhua L.). The Atlantic cod used in this study originated from a feeding trial, which found that fish fed a high starch diet contained relative more collagen type I, while fish fed a low starch (LS) diet contained relative more glycosaminoglycans (GAGs) in the connective tissue. FTIR spectra of pure commercial collagen type I and GAGs were acquired to identify spectral markers and compare them with FTIR spectra and images from connective tissue. Using principal component analysis, high and LS diets were separated due to collagen type I in the spectral region 1800 to 800 cm?1. The spatial distribution of collagen type I and GAGs were further investigated by FTIR imaging in combination with immunohistochemistry. Pixel‐wise correlation images were calculated between preprocessed connective tissue images and preprocessed pure components spectra of collagen type I and GAGs, respectively. For collagen, the FTIR images reveal a collagen distribution that closely resembles the collagen distribution as imaged by immunohistochemistry. For GAGs, the concentration is very low. Still, the FTIR images detect the most GAGs rich regions.   相似文献   

10.
Dietary flaxseed has been shown to have potent antiatherogenic effects in rabbits. The purpose of the present study was to investigate the antiatherogenic capacity of flaxseed in an animal model that more closely represents the human atherosclerotic condition, the LDL receptor-deficient mouse (LDLrKO), and to identify the cellular mechanisms for these effects. LDLrKO mice were administered a regular diet (RG), a 10% flaxseed-supplemented diet (FX), or an atherogenic diet containing 2% cholesterol alone (CH) or supplemented with 10% flaxseed (CF), 5% flaxseed (CF5), 1% flaxseed (CF1), or 5% coconut oil (CS) for 24 wk. LDLrKO mice fed a cholesterol-supplemented diet exhibited a rise in plasma cholesterol without a change in triglycerides and an increase in atherosclerotic plaque formation. The CS mice exhibited elevated levels of plasma cholesterol, triglycerides, and saturated fatty acids and an increase in plaque development. Supplementation of the cholesterol-enriched diet with 10% (wt/wt) ground flaxseed lowered plasma cholesterol and saturated fatty acids, increased plasma ALA, and inhibited plaque formation in the aorta and aortic sinus compared with mice fed a diet supplemented with only dietary cholesterol. The expression of proliferating cell nuclear antigen (PCNA) and the inflammatory markers IL-6, mac-3, and VCAM-1 was increased in aortic tissue from CH and CS mice. This expression was significantly reduced or normalized when flaxseed was included in the diet. Our results demonstrate that dietary flaxseed can inhibit atherosclerosis in the LDLrKO mouse through a reduction of circulating cholesterol levels and, at a cellular level, via antiproliferative and anti-inflammatory actions.  相似文献   

11.
The aim of the research was to determine the concentration of total protein and its fractions as well as the concentration of selected mineral components in the blood serum of male broiler chickens Cobb 500 fed diets with different cellulose content. Blood samples were collected for examination from the birds' pterygoid canal veins on their 42 day of age. There was no influence of cellulose preparation on the content of total protein and its fractions: albumins, alfa1-, alfa2-, beta-, gamma-globulins, albumin to globulin ratio, inorganic phosphorus, sodium, potassium, chloride and iron concentrations in blood serum. The highest calcium concentration (P < 0.05) was detected in the blood serum of males fed a diet with the highest cellulose content (0.75-0.95%). Simultaneously, a tendency of increased calcium content was observed along with an increased amount of pure cellulose in diets. The lowest magnesium level (P < 0.05) was observed in the blood of birds fed diets with the lowest amount of cellulose (0.25-0.45%). The magnesium level in the blood of birds fed a diet with higher amounts of cellulose did not considerably differ from the control group. Results from the current study suggest that introduction of a limited amount of pure cellulose into the diet of broiler chickens does not affect total protein concentration and protein fractions but can influence the mineral content in the blood serum.  相似文献   

12.
Cholesterol metabolism in rhesus monkey, squirrel monkey, and baboon   总被引:1,自引:0,他引:1  
The metabolism of cholesterol was studied in baboons, rhesus monkeys, and squirrel monkeys while they were being fed either a low fat, low cholesterol (basal) diet or the basal diet supplemented with saturated fat and cholesterol (atherogenic diet). When the diet was changed from basal to atherogenic, the mean total serum cholesterol concentration increased from 70 to 180 mg/dl in the baboon, from 168 to 283 mg/dl in the squirrel monkey, and from 144 to 608 mg/dl in the rhesus monkey. In animals fed the atherogenic diet, the percentage of dietary cholesterol absorbed was greatest in the rhesus monkey and least in the baboon. The fraction of the total body pool of cholesterol that was derived from the diet was greatest in the squirrel monkey and least in the baboon. The turnover of the body pool of cholesterol was several times faster in the squirrel monkey than in the baboon or the rhesus monkey when either dict was fed. The mean total fecal excretion of endogenous cholesterol and bile acid increased in all species on transition to the atherogenic diet; however, the relative contributions of the neutral and acidic fractions to the increase in total excretion differed among species. The difference in percentage of dietary cholesterol absorbed may, in part, account for the large differences in serum cholesterol during the atherogenic diet period. Comparison with other published results indicates that of these species cholesterol metabolism in the baboon is most like that in the human.  相似文献   

13.
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   

14.
目的探讨建立兔饵食性高脂血症模型的方法,观察高脂饮食对兔体重、死亡率及血脂变化情况。方法取普通级雄性新西兰大耳白兔,其中随机抽取10只作为普通饮食组,喂以普通饮食;其他动物给予高脂饮食,4周后,根据血清TC水平分为高脂饮食敏感组和高脂饮食非敏感组,继续喂养9周,观察三组间兔血清总胆固醇(TC)、甘油三脂(TG)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)的变化。结果与普通饮食组相比,高脂饮食敏感组在第4~13周时血清TC、TG、HDL-C、LDL-C水平显著升高(P〈0.01),高脂饮食非敏感组在第7~13周时,动物血清TC、HDL-C、LDL-C水平显著升高(P〈0.01),而高脂饮食非敏感组血清TG水平的改变无统计学意义(P〉0.05)。与高脂饮食敏感组相比,高脂饮食非敏感组家兔血清TC、TG、HDL-C和LDL-C水平的上升程度均显著低于高脂饮食敏感组动物(P〈0.01)。结论首次发现兔对高脂饮食敏感性存在差异,高脂饮食非敏感组家兔抗病能力、对环境的适应能力和耐受性均高于高脂饮食敏感组兔。与高脂饮食敏感组家兔相比,高脂饮食非敏感组家兔对高脂饮食耐受性强。  相似文献   

15.
Biochemical, histological and electron-microscopic examinations of the heart and the aorta of albino rats exposed to carbon disulphide in concentrations of 10, 50, 100 and 200 mg . m-3 were carried out. Changes in the metabolic and energetic processes in the myocardium and in the quantitative and qualitative characteristics of the connective tissue of the aortal vessel wall were observed. The established disorders follow the dose-effect dependence. The authors studied the effect of carbon disulphide in concentrations of 10 and 50 mg . m-3 on the electrophoretic spectrum of serum proteins, the quantitative and qualitative characteristics of fibrous structures in the myocardium and the aorta of albino rats fed on atherogenic diet (cholesterol, cholic acid and vitamin D2). The combination of carbon disulphide with the atherogenic factor leads to intensification of changes in the cardiovascular system and in serum proteins, observed after independent exposure to either of the factors. The combination of atherogenic diet and 10 mg . m-3 carbon disulphide induced symptoms of intoxication, decreased survival of the animals, and the developing sclerotic process was found to be more severe and to progress more rapidly than in animals subject to atherogenic diet alone. The obtained results testify to cardiovascular effect of carbon disulphide. The observed atherogenic effect of carbon disulphide in low concentrations is most probably connected with its direct effect on the myocardium and the vessels.  相似文献   

16.
Morphine-induced alterations in plasma and tissue cholesterol levels   总被引:1,自引:0,他引:1  
In rats fed a cholesterol-cholic acid supplemented diet, implantation of a 75 mg morphine pellet elevated total plasma cholesterol, raised low density lipoprotein (LDL) plus very low density lipoprotein (VLDL) cholesterol, and lowered high density lipoprotein (HDL) cholesterol levels. The resultant increase of the atherogenic index was accompanied by enhanced aortic cholesterol deposition. These alterations were prevented by daily administration of naltrexone (1.0 mg/kg, sc), and were not associated with hyperphagic or hepatotoxic actions of morphine. An increase in total plasma cholesterol and in LDL plus VLDL cholesterol was also observed in morphine pelleted rats maintained on a normal diet. The possible implications of opiate-induced hypercholesterolemia are discussed.  相似文献   

17.
The purpose of the present study was to test the hypothesis that lecithin:cholesterol acyltransferase (LCAT) deficiency would accelerate atherosclerosis development in low density lipoprotein (LDL) receptor (LDLr-/-) and apoE (apoE-/-) knockout mice. After 16 weeks of atherogenic diet (0.1% cholesterol, 10% calories from palm oil) consumption, LDLr-/- LCAT-/- double knockout mice, compared with LDLr-/- mice, had similar plasma concentrations of free (FC), esterified (EC), and apoB lipoprotein cholesterol, increased plasma concentrations of phospholipid and triglyceride, decreased HDL cholesterol, and 2-fold more aortic FC (142 +/- 28 versus 61 +/- 20 mg/g protein) and EC (102 +/- 27 versus 61+/- 27 mg/g). ApoE-/- LCAT-/- mice fed the atherogenic diet, compared with apoE-/- mice, had higher concentrations of plasma FC, EC, apoB lipoprotein cholesterol, and phospholipid, and significantly more aortic FC (149 +/- 62 versus 109 +/- 33 mg/g) and EC (101 +/- 23 versus 69 +/- 20 mg/g) than did the apoE-/- mice. LCAT deficiency resulted in a 12-fold increase in the ratio of saturated + monounsaturated to polyunsaturated cholesteryl esters in apoB lipoproteins in LDLr-/- mice and a 3-fold increase in the apoE-/- mice compared with their counterparts with active LCAT. We conclude that LCAT deficiency in LDLr-/- and apoE-/- mice fed an atherogenic diet resulted in increased aortic cholesterol deposition, likely due to a reduction in plasma HDL, an increased saturation of cholesteryl esters in apoB lipoproteins and, in the apoE-/- background, an increased plasma concentration of apoB lipoproteins.  相似文献   

18.
Dietary intake of industrially hydrogenated trans fatty acids (TFA) has been associated with coronary heart disease. Dietary flaxseed can inhibit atherosclerosis induced by dietary cholesterol. The aim of this study was to determine whether supplementing the diet with flaxseed could protect against atherosclerosis induced by a diet enriched in TFA. Low-density lipoprotein receptor-deficient (LDLr(-/-)) mice were fed 1 of 14 experimental diets for 14 wk containing one of two fat sources [regular (pork/soy) or trans fat] at two concentrations (4 or 8%) and supplemented with or without dietary cholesterol (2%), whole ground flaxseed, or one of the components of flaxseed [α-linolenic acid (ALA), defatted fiber, or lignan]. Adding flaxseed to the diet partially mitigated the rise in circulating cholesterol levels induced by the cholesterol-enriched diet. Atherosclerosis was stimulated by TFA and/or cholesterol. Including milled flaxseed to an atherogenic diet significantly reduced atherosclerosis compared with the groups that consumed cholesterol and/or TFA. ALA was the only component within flaxseed that could inhibit the atherogenic action of cholesterol and/or TFA on its own. Dietary flaxseed protects against atherosclerotic development induced by TFA and cholesterol feeding through its content of ALA.  相似文献   

19.
Effects of phenotype, sex, and diet on plasma lipids in LA/N-cp rats   总被引:1,自引:0,他引:1  
The LA/N-corpulent (cp) rat is a recently developed congenic strain which exhibits obesity. The effects of phenotype and sex on serum and lipoprotein lipid content were examined in LA/N-cp rats fed either a control or an atherogenic diet high in saturated fat and protein. Obese rats were pair-fed to equivalent lean animals. Results from this study indicate that sex, phenotype, and diet exert significant effects on plasma and lipoprotein cholesterol content. Plasma cholesterol levels were higher in obese compared with lean rats, females than in males, and rats consuming the atherogenic diet compared with the control diet. Plasma and lipoprotein triglyceride levels were significantly increased only in obese compared with lean animals. The increased plasma cholesterol and triglyceride was observed primarily in the chylomicron and very low density lipoprotein fractions. Increased levels of plasma cholesterol were not a result of increased dietary cholesterol absorption or increased liver cholesterol biosynthesis. These data suggest that LA/N-cp rats can serve as a unique rodent model for the study of the interrelationships between hyperlipidemia, obesity, and coronary heart disease.  相似文献   

20.
The two key enzymes, methylenetetrahydrofolate reductase and methionine synthase involved in methionine synthesis from homocysteine were studied in atherogenic diet fed mice. Methylenetetrahydrofolate reductase activity was elevated while methionine synthase was impaired in atherogenic diet fed group. Impaired methionine synthase activity would adversely affect the methionine synthesis from homocysteine, resulting in a rise in the homocysteine levels, which are atherogenic. This is reflected by the increased levels of very low density and low density lipoprotein cholesterol values and a higher ratio for total cholesterol to high density lipoprotein cholesterol.  相似文献   

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