花椒精有效成分对高脂膳食大鼠脂质代谢的影响

目的研究花椒精有效成分对高脂膳食大鼠脂质代谢的影响及作用机制。方法用高脂饲料饲喂大鼠,并分别给与花椒精和含花椒精组相同剂量的花椒挥发油及花椒麻素灌胃4w后,检测大鼠血脂、肝脂及粪便中胆汁酸和中性固醇含量;用RT-PCR法检测肝脏及回肠中与脂质代谢相关基因m RNA的表达。结果与模型组相比,花椒精和花椒麻素组显著降低大鼠血清及肝脏中胆固醇(TC)和甘油三酯(TG)(P0.05),增加粪便中胆汁酸及中性固醇含量(P0.05),有效下调肝脏和回肠中3-羟基-3-甲基-戊二酰Co A还原酶(HMG-Co A R)及回肠胆盐转运蛋白(ASBT)等基因m RNA表达(P0.05),显著上调肝脏7α–羟化酶(CYP7A1)及回肠法尼酯受体(FXR)m RNA表达(P0.01);花椒挥发油组可显著降低大鼠血清及肝脏TG水平(P0.05),增加粪便中性固醇含量,但增加了肝脏TC和减少粪便中胆汁酸含量,下调肝脏CYP7A1和HMG-Co A还原酶m RNA表达,上调肝脏和回肠FXR m RNA表达(P0.05)。结论花椒精、花椒挥发油及花椒麻素对高脂膳食大鼠脂质代谢紊乱均有良好的改善作用,其中花椒麻素效果最佳,其可能机制与上调肝脏中胆固醇分解、下调胆固醇合成及回肠胆汁酸重吸收的相关基因表达有关。     

复合膳食纤维对大鼠脂代谢的短期作用

目的：　通过研究复合膳食纤维（ Ｄ Ｆ Ｃ） 对大鼠脂代谢的影响,以寻求降脂效果良好的最佳 Ｄ Ｆ Ｃ 比例配方,为进一步研究 Ｄ Ｆ Ｃ 可能的作用和机理提供依据。方法：　雌性、断乳 Ｓ Ｄ 大鼠４２ 只,经高脂饲料诱导成高脂血症模型后,按体重和血清总胆固醇水平均衡的原则分为６ 组,分别给予总膳食纤维水平一致但比例构成不同的四种复合膳食纤维,以高脂饲料作为对照组,观察其对大鼠血浆和肝脏脂质、粪中胆汁酸含量的影响。结果：　１ ．四种复合膳食纤维对大鼠摄食及生长发育均无不良影响。２ ．可溶性纤维（ Ｓ Ｄ Ｆ） 与不可溶性纤维（ Ｉ Ｓ Ｄ Ｆ） 比例为４ ．４ ,２ ．０ 及１ ．０ 的三种 Ｄ Ｆ Ｃ 均能显著降低高脂血症大鼠的血胆固醇（ Ｔ Ｃ） 、低密度脂蛋白胆固醇（ Ｌ Ｄ Ｌ Ｃ） 及肝胆固醇（ Ｌ Ｃ Ｈ） 水平,且这种作用与 Ｓ Ｄ Ｆ／ Ｉ Ｓ Ｄ Ｆ 比值之间密切相关;以 Ｓ Ｄ Ｆ／ Ｉ Ｓ Ｄ Ｆ＝２ ．０ 的 Ｄ Ｆ Ｃ Ｂ 作用最佳。３ ．各 Ｄ Ｆ Ｃ 均能增高大鼠血浆高密度脂蛋白胆固醇（ Ｈ Ｄ Ｌ Ｃ） 及 Ｈ Ｄ Ｌ Ｃ 与 Ｌ Ｄ Ｌ Ｃ 的比值,仍以 Ｓ Ｄ Ｆ Ｆ／ Ｉ Ｓ Ｄ Ｆ＝ ２ ．０ 的 Ｄ Ｆ Ｃ Ｂ 作用最为显著。４ ．各组动物的粪胆汁酸排泄量高     

魔芋精粉对高脂饲料喂养大鼠的脂质代谢及血液粘度的影响

用高脂饲料加入魔芋精粉喂饲健康雄性SD大鼠6周，观察魔芋精粉对大鼠血脂水平及血液粘度的影响，结果表明，魔芋精粉能有效地降低高脂组大鼠血清总胆固醇，甘油三酯及血清酯质过氧化物，同时可提高高密度脂蛋白胆固醇及高密度脂蛋白胆固醇／总胆固醇比值，降低大鼠血液粘度，但对大鼠摄食量及生长无不良影响。     

高直链玉米淀粉对卵巢切除大鼠体内胆固醇代谢影响的研究

目的:研究高直链玉米淀粉(HACS)对因雌性激素缺乏引起的高胆固醇血症的影响。方法:将36只Wistar成年雌鼠随机分为6组,5组进行双侧卵巢切除手术(OVX),分别喂食不添加(对照)和添加10%、20%、30%、40%HACS的饲料,另1组进行卵巢伪切除手术,喂食不添加HACS的对照饲料。实验喂养4w后解剖,测定血清和肝脏中胆固醇、甘油三酯浓度、肝脏胆固醇羟化酶(CYP7)活性以及小肠、盲肠中胆汁酸总量和粪中胆汁酸排泄量等指标。结果:OVX组大鼠血浆和肝脏中胆固醇和甘油三酯浓度显著高于伪切除组大鼠。与对照饲料组相比,饲料中添加20%和30%HACS能显著降低血清中甘油三酯浓度;添加30%和40%HACS能显著降低去势大鼠血清胆固醇;添加30%和40%HACS显著增加了小肠中胆汁酸含量和粪中胆汁酸排泄量;各组间CYP7活性没有显著性差异。结论:HACS对因雌性激素缺乏引起的高胆固醇血症有明显降低效果,可能的作用机制是通过增加肠道中胆汁酸总量和粪中胆汁酸的排泄量来降低血液中胆固醇浓度。     

果胶对大鼠脂质代谢、脂质过氧化和血浆纤维蛋白原的影响

观察可溶性膳食纤维对大鼠脂质代谢、脂质过氧化和血浆纤维蛋白原的影响。健康雄性大鼠饲以高脂饲料同时添加１０％果胶,喂饲１２周后测其血、肝中总胆固醇（ＴＣ）、甘油三酯（ＴＧ）、丙二醛（ＭＤＡ）、超氧化物歧化酶（ＳＯＤ）和血浆纤维蛋白原含量。结果表明果胶能明显降低血、肝中ＴＣ、ＴＧ、ＭＤＡ含量,使肝中ＳＯＤ活力升高,同时果胶组血浆纤维蛋白原水平较对照亦明显下降。结果提示可溶性膳食纤维对动脉粥样硬化和冠心病具有良好的防治作用。     

优化复合纤维配伍沙棘果渣对高胆固醇血症大鼠脂代谢的影响

[目的]研究优化复合纤维配伍沙棘果渣对高胆固醇血症大鼠脂代谢的长期影响,探讨沙棘果渣的降脂作用. [方法]断乳SD大鼠32只,雌雄各半,经高脂饲料诱导成高脂血症模型后,按体重和血浆总胆固醇均衡的原则分为4组,A、B组分别为高脂饲料对照组和正常饲料对照组,C组为5%的优化复合纤维组,D组为4%沙棘果渣+5%的优化复台纤维组.实验期3个月末,观察各组大鼠血清、肝脏脂质和粪胆汁酸代谢的变化. [结果]优化复合纤维细可显著降低大鼠的体重(P＜0.05),优化复台纤维组和添加沙辣果渣组均可显著降低大鼠的血浆总胆固醇和肝脏胆固酯水平(P＜0.05),但添加沙棘果渣组的降脂效果更优(P＜0.05);添加沙棘果渣组大鼠粪胆汁酸的含量显著低于优化复合纤维组(P＜0.05). [结论]沙棘果渣配伍优化复合纤维对高脂血症大鼠具有长期稳定的降脂效果,且降脂效果优于优化复合纤维.     

复合纤维素降脂效果观察及机理探讨

以燕麦麸、消棘皮等为主要原料，研究含不同比例可溶性膳食纤维的３种复合纤维素对大鼠脂质代谢和机体过氧化反应的影响。将ＳＤ雌性大鼠制成高脂模型分为４组，以高脂饲料作为对照组（Ａ）。喂养４周后测定其血液及肝中脂质水平及ＡＰＯ－Ａｌ、ＡＰＯ－Ｂ、粪胆汁酸盐及ＬＰＯ含量：结果表明：３种复合纤维素均能有效地降低高脂大鼠血ＴＣ、ＴＧ、ＬＤＬ－ｃ及ＡＰＯＢ、ＬＰＯ水平，并提高ＨＤＬ－ｃ含量。提示利用不同膳食纤维特点组成的复合纤维素能用于降低人群的血脂水平和ＬＰＯ水平，对于动脉粥样硬化和心血管疾病的防治具有重要意义。     

大豆异黄酮对高脂去卵巢大鼠肝脏脂质的影响

目的　观察大豆异黄酮 (SI)对进食高脂饲料的去卵巢大鼠脂质和肝组织过氧化状态的影响。方法　 50只SD大鼠随机分为 5组 ,分别接受假手术 +基础饲料 ;去卵巢 +高脂饲料 ;去卵巢 +高脂饲料 +SI 3个剂量组 2 0 ,60 ,180mg/ (kg·bw·d)处理 ,实验期 8周。 结果　与模型组比较 ,SI可显著抑制高脂饲料所致的去卵巢大鼠肝脏和血清甘油三酯水平升高 (P <0 .0 5) ,但对肝脏总胆固醇变化无影响 (P >0 0 5)。与假手术组和模型组比较 ,SI降低肝脏MDA含量均有显著性差异 (P <0 0 1)。结论　SI对去卵巢大鼠肝脏高甘油三酯有降低作用 ,并能改善高脂饮食所致的肝脏过氧化状态异常 ,减轻对机体的过氧化损伤     

重组复合纤维对高脂血症大鼠脂代谢的影响

目的 :　研究不同剂量水平的重组复合纤维 ( AFC)对高脂血症大鼠脂代谢的影响 ,从分子水平探讨 AFC降脂机制 ,寻找安全剂量。方法 :　断乳 SD大鼠 60只 ,雌雄各半 ,经高脂饲料诱导成高脂血症模型后 ,按体重和血浆总胆固醇均衡的原则分为 5组 ,以高脂饲料和正常饲料为对照组 ,其余三组分别饲以不同水平 ( 5%、1 0 %、2 0 % )的重组复合纤维 ,观察重组复合纤维对大鼠血清、肝脏胆固醇及粪胆汁酸代谢的影响 ,应用半定量逆转录聚合酶链反应 ( RT- PCR)观察肝脏Apo- AI基因表达的情况。结果 :　 ( 1 ) 2 0 %的重组复合纤维可显著降低大鼠的体重 ;( 2 )不同剂量水平的重组复合纤维均可显著降低大鼠的血浆总胆固醇 ( TC)和肝脏胆固醇 ( LCH)水平 ,2 0 % AFC的作用最强 ;( 3)大鼠粪胆汁酸的含量与 AFC的剂量水平成反比例 ;( 4 )高剂量水平的重组复合纤维可显著促进肝脏 Apo- AI基因的表达 ,而低剂量水平的重组复合纤维不能刺激其表达。结论 :　各剂量水平的重组复合纤维均具有长期稳定的降脂效果 ,高剂量水平的重组复合纤维降脂作用最强。肝脏载脂蛋白 - AI基因表达增加可能是重组复合纤维降脂机制之一。     

辣椒素对糖尿病大鼠脂质代谢的影响

目的探讨辣椒素对糖尿病大鼠脂质代谢的影响。方法以链脲佐菌素(STZ)诱导的糖尿病大鼠为模型,分别给予3,6,9 mg/(kg bw·d)的辣椒素灌胃4 w后,检测大鼠血脂、肝脂、粪便中性固醇、粪便和小肠内容物中胆汁酸含量以及肠道脂肪酶活性的变化;并观察肝脏组织病理切片。结果与模型对照组相比,辣椒素能显著性降低肠道脂肪酶的活性,增加粪便中胆汁酸含量(P0.05),降低大鼠血清和肝脏中胆固醇(TC)、甘油三酯(TG)及增加粪便中性固醇含量,但组间无剂量效应。结论辣椒素对糖尿病大鼠脂质代谢紊乱具有良好的改善作用,其中以中和高剂量效果最佳,其可能机制是辣椒素促进了大鼠粪便中胆汁酸和中性固醇的排出,抑制了肠道脂肪酶的活性,从而阻止脂质在肝脏的积聚。     

Dietary soluble fiber and cholesterol affect serum cholesterol concentration, hepatic portal venous short-chain fatty acid concentrations and fecal sterol excretion in rats.

Sprague-Dawley rats were fed diets containing 7.5% dietary fiber as cellulose (control), pectin, psyllium or oat bran with or without 0.3% added cholesterol for 3 wk. Among rats fed cholesterol, liver total lipid and cholesterol concentrations were significantly lower in groups fed pectin, psyllium and oat bran compared with cellulose-fed controls. Cholesterol feeding resulted in significantly greater liver cholesterol in rats fed cellulose, psyllium and oat bran but not in those fed pectin. Among rats fed cholesterol, total serum cholesterol levels were significantly lower in those fed pectin than in those fed psyllium, oat bran or cellulose. When cholesterol was fed, the oat bran-fed group had significantly higher butyrate and the pectin-fed group had significantly higher propionate concentrations in the hepatic portal vein than did cellulose-fed controls. The groups fed psyllium, oat bran and pectin all had significantly higher fecal neutral sterols than did the cellulose-fed group when cholesterol was fed. Without dietary cholesterol only pectin-fed rats had significantly higher fecal excretion of neutral sterols than those fed cellulose. Dietary fiber did not influence fecal acidic sterol excretion. However, the addition of cholesterol to these fiber diets was accompanied by a significantly higher bile acid excretion than that of animals fed cellulose without cholesterol. The results of this study indicate that soluble dietary fibers may exert their hypocholesterolemic effect by increasing excretion of fecal neutral sterols.     

Stimulation of chenodeoxycholic acid excretion in hypercholesterolemic mice by dietary taurine

The effects of dietary taurine on fecal steroid excretion and bile acid pool size were investigated in Jcl: ICR strain mice. The mice were fed on semi-purified diets for five weeks: a cholesterol-free diet (Standard), a lithogenic diet containing 0.5% cholesterol and 0.25% sodium cholate (C-CA) and a lithogenic diet supplemented with 5% taurine (C-CA + 5% taurine). The changes in fecal steroid excretion were studied as a function of time and the bile acid pool size was estimated. Dietary taurine affected fecal bile acid excretion both quantitatively and qualitatively. No change in bile acid pool size was observed. The fecal excretion of bile acids increased in taurine-supplemented mice. The increase in the fecal neutral steroid excretion was less than that in C-CA fed mice. The proportion of chenodeoxycholic acid (CDCA) and the related bile acids to total bile acids increased both in the fecal bile acids and in the bile acid pool. Therefore, the protective effect of dietary taurine against cholesterol gallstone formation may be related to the stimulation of bile acid synthesis, especially of CDCA and related compounds.     

Effect of wheat bran, pectin and cellulose on the secretion of bile lipids in rats

We assayed the lipid content of bile from rats that had been fed either a standard diet (5% fat) or a high fat diet (25% fat, 1.2% cholesterol) in the presence or in the absence of various dietary fibers (namely, wheat bran, pectin and cellulose). The cholesterol concentration in bile from rats fed the high fat diet plus wheat bran or pectin was lower than that of the rats fed the high fat, high cholesterol diet without fiber. Bile phospholipids did not vary significantly from one group to another. In comparison to the standard diet, the high fat, high cholesterol diet led to a greater ratio of primary to secondary bile salts and a higher level of glycoconjugates. The observed differences may be explained by a variation in the metabolism of bile salts brought about by the difference in diet.     

魔芋精粉在二甲肼诱发大鼠结肠癌中对肠道菌群、中性类固醇、短链脂肪酸的影响

采用ＳＤ大鼠实验，结果未显示魔芋精粉对结肠癌发生率的干预作用，与组织病理检查结果一致。     

Effect of dietary soluble fiber on neurohormonal profiles in serum and brain of rats

This study was conducted to investigate the effect of dietary soluble fiber administration and /or high fat diet on serum and brain neurohormonal profiles, adipose tissue mass and body weight gain in Sprague-Dawley rats. Four groups of rats were respectively fed 10% fat diet (C), 10% fat plus pectin diet (P), 20% fat diet (HFC) and 20% fat plus pectin diet (HFP) for 4 weeks. In HFP group, the food and energy intake, body weight gain, FER including fecal excretion were the smallest (p<0.05). Serum HDL-cholesterol, triglyceride and glucose level were also the lowest in HFP group (p<0.05). The weight of brain, epididymal fat pad and adrenal gland except liver didn''t show any significant differences among groups. Interestingly serum norepinephrine concentration of HFP group tended to be higher, but dopamine concentration tended to be lower than those of HFC group. However serum catecholamine concentration didn''t show any significant differences among all groups. Norepinephrine and epinephrine contents of right portion of midbrain of P and HFP groups were remarkably lower than those of the C group. These results suggested that soluble fiber pectin consumption might affect neurohormonal profiles in serum and brain according to dietary fat level.     

补充牛磺酸对正常大鼠脂代谢的影响

为研究不同牛磺酸水平对正常大鼠血脂的影响 ,将 40只断乳SD大鼠用基础饲料喂养一周后 ,按体重和血浆总胆固醇均衡的原则分为 4组 ,对照组进食正常饲料 ,其余 3组分别在基础饲料的基础上添加不同水平 (6、1.35和 3g kg饲料 )的牛磺酸 ;实验 5周后 ,观察牛磺酸对大鼠血脂的影响。结果表明 ,与正常对照组相比 ,不同剂量的牛磺酸均可显著影响大鼠血浆脂质水平 ;6g kg牛磺酸降低血清总胆固醇、低密度脂蛋白胆固醇效果最明显 ,13.5g kg牛磺酸可显著降低血清甘油三酯、载脂蛋白 B水平 ,促进粪胆汁酸排泄 ;30g kg牛磺酸对降低大鼠肝脏总胆固醇、升高血清载脂蛋白效果较好。     

Effect of pectin,type of fat,and growing rate on lipid metabolism in rats

The effects of pectin, type of fat, and growing rate on lipid metabolism were investigated. Male Wistar rats weighing 122±1 g were fed ad libitum for 8 weeks a nutritionally adequate diet containing 0.5% cholesterol, 12% fat, either corn oil (CO) or beef tallow (BT), and 5% fiber, either cellulose (CE) or pectin (PE). At the end of the feeding period, the rats in each diet group were divided according to their body weight into two groups, slow-growing (range 360 g to 426 g, SG) or fast-growing (range 444 g to 479 g, FG). The difference between the means of the two groups was highly significant (P<0.01). Dietary pectin compared to cellulose lowered liver cholesterol and total liver lipid. However, there was a significant interaction between the type of dietary fiber and the type of dietary fat so that liver total lipid concentration was lower in the BT-fed than in the CO-fed rats. Liver triglyceride level (only measured in the FG group) was not influenced by fiber but was markedly higher in the CO-fed than the BT-fed rats. A significant triple interaction between type of dietary fiber, type of dietary fat, and growth rate was observed for serum cholesterol. Serum cholesterol was significantly lower in the PE-fed than the CE-fed animals except when BT was the dietary fat fed the SG rats and CO was the dietary fat fed the FG rats. The present results suggest that in determining lipid metabolism the interaction between extrinsic factors and intrinsic factors such as growing rate should be taken into consideration.     

Effects of manufactured soluble dietary fiber from Quercus mongolica on hepatic HMG-CoA reductase and lipoprotein lipase activities in epididymal adipose tissue of rats fed high cholesterol diets

This study investigated the effect of a manufactured soluble dietary fiber on lipid metabolism in rats fed high cholesterol diets. Soluble dietary fiber was prepared from wood chips of oak (Quercus mongolica). Male Sprague-Dawley rats weighing 100 +/- 10 g were randomly assigned to either a normal diet or five high cholesterol diets containing 1% cholesterol and different fiber supplements. The high cholesterol groups were subdivided into fiber-free diet (FF), 5% pectin (5P), 10% pectin (10P), 5% manufactured soluble dietary fiber (5QM), and 10% manufactured soluble dietary fiber (10QM) groups. Total serum cholesterol concentrations in all soluble dietary fiber-supplemented groups were lower than in the FF group. The high-density lipoprotein-cholesterol concentration in the FF group was significantly lower, compared with the normal group, but was increased in groups supplemented with soluble dietary fiber. Low-density lipoprotein-cholesterol levels and the atherogenic index had the same tendency as total cholesterol concentration. Compared with the FF group, in the 5P, 5QM, 10P, and 10QM groups hepatic triglyceride concentrations were 12%, 16%, 20%, and 24% lower, respectively, and hepatic cholesterol concentrations were 48%, 52%, 52%, and 58% lower, respectively. Hepatic 3-hydroxy-3-methylglutaryl-CoA reductase activity in the soluble fiber groups was significantly higher than in the FF groups, but lower than the normal group. When hepatic tissue was observed under a light microscope, the FF group had completely formed lipomas in the hepatic tissue, which led to fat deposits and then a fatty liver. The size and number of lipomas were lower in the soluble dietary fiber-fed groups, as compared with the group not fed dietary fiber. In conclusion, improvements in lipid metabolism were observed as a result of the manufactured soluble dietary fiber from the oak chips, and were similar to that seen for pectin. The preparation method for the soluble dietary fiber from oak chips successfully produced a functional soluble fiber.     

Lowering serum cholesterol level by feeding a 40% ethanol-eluted fraction from HP-20 resin treated with hot water extract of adzuki beans (Vigna angularis) to rats fed a high-fat cholesterol diet

ObjectiveHot water extract of adzuki beans (Vigna angularis) was subjected to HP-20 resin chromatography. The fraction eluted from the column using 40% ethanol (EtEx.40) was investigated by its effect on serum lipids in rats fed a high-fat cholesterol and/or cholesterol-free high-fat diet.MethodsThe rats were divided into 4 groups. Groups 1 and 2 were fed a high-fat cholesterol diet with or without 3.5% EtEx.40 for 2 wk. Group 3s and 4 were fed a high-fat cholesterol-free diet with or without 3.5% EtEx.40 for 2 wk.ResultsIn the high-fat-cholesterol diet groups, there was no significant difference in food intake in the experimental diet group when compared with the control group. Serum total cholesterol level was significantly decreased in the rats fed the EtEx.40 diet, but there was no difference in fecal excretion of cholesterol and bile acid between the two dietary groups. Conversely, in the high-fat cholesterol-free diet groups, ingestion of EtEx.40 reduced serum triacylglycerol concentration.ConclusionIngestion of EtEx.40 suppressed serum cholesterol level in rats fed the high-fat cholesterol and serum triacylglycerol level in rats fed the high-fat cholesterol-free diet. These mechanisms did not become clear in this experiment.     

Effect of dietary ascorbic acid, cholesterol and PCB on cholesterol and bile acid metabolism in a rat mutant unable to synthesize ascorbic acid

The effect of acute or chronic ascorbic acid deficiency on the activity of hepatic cholesterol 7 alpha-hydroxylase and fecal excretion of bile acids was investigated in ODS-od/od (OD) rats (a rat mutant unable to synthesize ascorbic acid) fed a purified basal diet or purified diets containing either cholesterol (2%) or polychlorinated biphenyl (PCB) (200 mg/kg). In OD rats, the dietary requirement of ascorbic acid to maintain normal growth and normal levels of cholesterol in serum and liver is about 300 mg of ascorbic acid/kg diet. In OD rats fed the basal diet, acute or chronic ascorbic acid deficiency did not affect the activity of hepatic cholesterol 7 alpha-hydroxylase and fecal excretion of bile acids. However, in OD rats fed diets containing either cholesterol or PCB, acute ascorbic acid deficiency caused a higher level of serum cholesterol, a lower activity of hepatic cholesterol 7 alpha-hydroxylase and a lower excretion of fecal bile acids than in OD rats fed a basal diet containing an adequate level of ascrobic acid. It is concluded that acute ascorbic acid deficiency causes a hypercholesterolemia due to the depression of bile acid synthesis in OD rats fed a purified diet with cholesterol or PCB.