重组复合膳食纤维对大鼠小肠形态结构影响

目的研究不同剂量重组复合膳食纤维对高脂血症大鼠肠道形态结构的影响。方法健康、断乳SD大鼠60只,雌雄各半,经高脂饲料诱导形成高脂血症模型后,按体重及血胆固醇水平均衡的原则分为5组,其中2组分别以基础饲料及高脂饲料作为阴性和阳性对照组,其余3组为5%,10%,20%不同剂量的重组复合膳食纤维,实验期90d,实验期末,用光镜、电镜形态观察及测量分析的方法观察大鼠肠道形态结构。结果20%剂量水平的重组复合膳食纤维可增加粪重（P〈0.05）,而5%,10%重组复合膳食纤维却可减轻粪重（P〈0.05）;与高脂对照组比较,20%剂量水平的重组复合膳食纤维组小肠壁重量显著增加,5%,10%剂量水平组动物小肠壁重量明显减轻,差异均有统计学意义（P〈0.05）;10%,20%剂量组动物的小肠粘膜肌层增厚（P〈0.05）,10%剂量组动物小肠绒毛略有变短、变宽,20%剂量组的动物小肠绒毛出现水肿,排列紊乱,线粒体肿胀。结论长期摄入低剂量重组复合膳食纤维对大鼠肠道的形态结构无明显影响,但高剂量可能会对肠道的形态结构产生不利影响。     

复合膳食纤维对高胆固醇血症大鼠肝脏的影响

目的 观察复合膳食纤维(DFC)对高脂血症大鼠肝脏结构及功能的长期影响。方法 健康成年SD大鼠84只，雌雄各半。经高脂饲料诱导形成高脂血症模型后，按体重及血胆固醇水平均衡的原则分为7组，其中2组分别以基础饲料及小麦纤维作为正常和高脂对照组，其余5组给不同剂量的DFC，实验期为3个月。通过生化分析及形态观察的方法，研究DFC对大鼠肝脏结构与功能的影响。结果(1)实验第60d时，DFC含量最高的G组(64％DFC)的血浆ALT活性显高于正常和高脂对照组，其余各DFC组的血浆ALT活性、各DFC组AST活性与正常及高脂对照组比较均无显性差异；(2)实验第90d时，较高剂量的3组(分别含DFCl6％，32％和64％)的血浆ALT、AST活性显高于正常对照组，其中最高剂量组的血浆ALT活性显高于高脂对照组，而较低剂量的2组(DFC含量分别为4％，8％)的血浆ALT、AST活性在实验各个阶段与对照组比较均无显性差异；(3)各DFC组的血浆ALT及AST活性在实验第60d及90d时均随DFC含量的增加而增高，呈现明显的剂量—反应关系；(4)各剂量DFC组肝细胞脂肪变性不明显，但呈现不同程度的气球样变，较高剂量组(32％)肝细胞可见到嗜酸性变。结论 长期摄入高剂量DFC会导致高脂血症大鼠肝脏形态结构和功能的改变，因此实际应用时应该以低剂量为宜。     

重组复合纤维对大鼠脂代谢及消化道结构的影响

目的　了解重组复合纤维 (AFC)对高脂血症大鼠脂代谢及消化道结构功能的影响。方法　雄性、断乳 Wistar大鼠 2 8只 ,体重 80～ 1 0 0 g,经高脂饲料诱导成高脂模型后 ,按体重和血浆总胆固醇均衡的原则分为 4组 ,分别饲以总纤维水平一致的重组复合纤维 (AFC)和复合膳食纤维(DFC) ,以高脂饲养和正常饲料为对照组 ,观察 AFC对大鼠脂质代谢及肝脏、小肠结构与功能的影响。结果　 1、AFC不影响大鼠的生长发育 ;2、AFC可显著降低大鼠血浆总胆固醇 (TC)、极低密度脂蛋白胆固醇 (VLDL- C)、低密度脂蛋白胆固醇 (LDL- C)、肝脏胆固醇 (LCH)水平 ;3、AFC可显著升高高密度脂蛋白胆固醇 (HDL - C)水平和 HDL- C/LDL- C比值 ;4、AFC能显著降低血浆 GPT、GOT活性 ;5、病理学观察未发现 AFC对肝脏、小肠的损害作用。结论　由燕麦麸、瓜儿豆胶为主要原料制成的 AFC具有较好的降脂效果 ,且各项功能均优于 DFC。     

裙带菜膳食纤维对高血脂大鼠血管内皮功能的影响

目的研究裙带菜可溶性膳食纤维对高脂血症大鼠内皮功能的影响。方法40只大鼠分为4组(n=10):正常对照组,高脂模型组,膳食纤维低剂量组(5%),膳食纤维高剂量组(10%);经裙带菜可溶性膳食纤维处理8w后,检测离体血管的内皮依赖性舒张效应,血浆丙二醛(MDA),一氧化氮(NO),内皮素-1(ET-1)水平,并用Western blotting检测内皮型一氧化氮合酶(eNOS)蛋白表达水平。结果裙带菜可溶性膳食纤维显著降低MDA,ET-1水平,显著改善内皮功能及血浆NO的水平并伴随着eNOS蛋白表达水平的上调。结论裙带菜可溶性膳食纤维能改善高脂血症大鼠的血管内皮功能,这可能与其降低ET-1水平,增加NO的产生有关。     

蛋白质对呼吸肌营养治疗的实验研究

本实验观察到营养不良大鼠膈肌Pt,Po显著下降,FT纤维萎缩重于ST纤维,肌原纤维疏松,线粒体肿胀、空化。分组经肠道给予高蛋白和低蛋白营养治疗4周后,两组大鼠膈肌Pt、Po及形态学改变均可恢复,高蛋白组膈肌收缩力、FT纤维横断面积恢复显著优于低蛋白组,接近正常水平。     

重组复合纤维对高脂血症大鼠肝脏结构和消化道功能的长期影响

目的：为研究不同剂量水平的AFC对高脂血症大鼠肝脏结构和消化道功能的长期影响。方法：将断乳SD大鼠60只,经,高脂饲料诱导成高脂模型后,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3组分别饲以不同水平（5％,10％,20％）的理组复合纤维（AFC）,观察AFC对大鼠消化道功能以及肝脏的病理切片的影响。结果：各剂量组AFC均可显降低大鼠的摄食,20％剂量水平的AFC可增加粪重,而5％,10％ AFC却可减轻粪重;与高脂对照组相比,不同剂量水平的AFC均可显6降低大鼠血浆GPT,GOT水平;各组肝重均显低于高脂对照组,并呈一反应关系,20％剂量水平的AFC可命名小肠壁重量增加,而5％,10％AFC可减轻小肠壁重量;20％剂量水平的AFC可造成大鼠肝脏混浊肿胀和脂肪变性。结论：提示：长期摄入中低剂量的AFC对肝脏,消化道没有损伤;高剂量水平的AFC却对机体有一定的副作用。     

高脂膳食诱导的大鼠肥胖对小肠黏膜糖吸收功能的影响

目的探讨高脂膳食诱导肥胖的发生是否与小肠黏膜糖类消化及吸收功能的改变相关联。方法 46只雄性SD大鼠随机分为高脂组(n=31)与正常对照组(n=15),分别用高脂饲料和基础饲料饲养24周。24周后高脂饲料组大鼠根据体重分为肥胖组(n=16)及肥胖抵抗组(n=10)。测定大鼠的体重及腹腔脂肪湿重、空腹血糖水平、小肠黏膜麦芽糖酶及蔗糖酶活性。免疫组织化学法、RT-PCR法及蛋白质免疫印迹法检测大鼠小肠黏膜中Na+-依赖型葡萄糖转运蛋白(SGLT-1)的表达水平。结果肥胖组大鼠的体重、腹腔脂肪湿重、空腹血糖水平、小肠黏膜麦芽糖酶活性及SGLT-1蛋白表达量显著高于正常对照组及肥胖抵抗组(P<0.05)。3组大鼠小肠黏膜蔗糖酶活性无明显差异(P>0.05)。肥胖组大鼠小肠黏膜SGLT-1 mRNA的表达水平与正常对照组及肥胖抵抗组比较分别增加了12.5%和23%,但差异无显著性(P>0.05)。结论高脂膳食诱导的大鼠肥胖与小肠黏膜中麦芽糖酶活性增强及糖吸收的关键分子SGLT-1的表达增加相关联。     

猪油与豆油对大鼠主动脉影响的扫描电镜观察

本实验观察了猪油与豆油对大鼠血脂水平和主动脉形态学改变的影响。成年雄性Ｗｉｓｔａｒ大鼠２４只分为猪油组、豆油组和对照组。观察结果表明：饲以高脂膳食２０天后，高脂组大鼠血清胆固醇水平显著高于对照组，猪油组显著高于豆油组。此后４０天，各组动物血清胆固醇含量维持在相对稳定的水平。至６０天时，在扫描电镜下可见高脂组大鼠主动脉发生病变，主要内皮细胞肿胀变形，排列紊乱，偶可见微血栓形成。猪组病变重于豆油组。     

烧伤后早期肠道营养对大鼠小肠粘膜保护作用的形态学观察

目的：为深入了解烧伤后期肠道地小肠粘膜保护作用的形态学变化。方法：采用计算机图像分析仪、透射电及冰冻蚀刻得型技术，对严重烧伤大鼠早期喂养（ＥＦ）、延迟喂养（ＤＦ）后小肠粘膜从光镜结构数量到超微结构质量的变化进行观察分析。结果：ＤＦ组空肠粘膜厚度、绒毛高度较ＥＰ组降低，电镜观察示肠上皮细胞间囊性扩张，微绒毛坏死脱落，线粒体空化、嵴断裂、冰冻刻刻复型观察示细胞间紧密连接松散紊乱，而ＥＦ组上述变化时间减     

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     

番茄红素对高同型半胱氨酸血症大鼠血管内皮功能的影响和机制研究

目的研究番茄红素(Lyc)预防高同型半胱氨酸血症(HHcy)致大鼠动脉粥样硬化(AS)的作用机制。方法50只SD雄性大鼠分为正常对照组(NC),HHcy对照组n(HC),HHcy+低(HL1)、中(HL2)、高剂量Lyc组(HL3)。NC组给予AOAC配方饲料,其余各组则给予在AOAC配方基础上添加3%L-蛋氨酸的饲料。HL1、HL2、HL3组按体重每日分别给予Lyc10、15、20mg/kgbw,实验期12w。分析血清Hcy、NO、一氧化氮合酶(NOS)、内皮素-1(ET-1),丙二醛(MDA)、·OH、H2O2,血管细胞粘附分子-1(VCAM-1)、单核细胞趋化因子-1(MCP-1)、白介素-8(IL-8)含量。处死动物,取腹主动脉做NF-κB测定和病理学检查。结果除了NC组外,HHcy各组大鼠血清Hcy含量均随时间延长而显著提高;HC组NO含量显著低于NC组,而ET-1含量显著高于NC组,HL2和HL3组NO含量显著高于HC组,而ET-1含量则明显低于HC组,各组间NOS含量无明显差异。病理学检查显示,HC组和HL1组主动脉内膜中有泡沫细胞聚集,有脂肪颗粒沉着,HL2组、HL3组和NC组主动脉内膜完整,无泡沫细胞和脂肪颗粒。HC和HL1组血清MDA和H2O2含量显著高于NC组,HL2和HL3组则明显低于HC组,HL2和HL3组H2O2含量还显著低于HL1组。与HC组相比,HL2和HL3组血清·OH含量显著降低;HC组VCAM-1、MCP-1和IL-8含量显著高于NC组,HL1、HL2和HL3组则明显低于HC组;HC组NF-κB的表达显著高于NC组,HL1、HL2和HL3组则明显低于HC组。结论Lyc可以通过直接淬灭活性氧,抑制NF-κB的激活,减少炎性因子的表达,来改善血管内皮功能,阻止AS的发生。     

谷氨酰胺对感染时机体营养代谢的作用

目的 研究谷氨酰胺(Gln)对感染时机体营养代谢的调节作用。方法采用右颈内静脉插管、盲肠结扎加穿孔法，建立近交系Wistar大鼠腹腔感染模型。实验组(n=16)采用Gln强化的完全肠外营养(TPN)，对照组(n=16)行常规TPN。观察10d，检测粘膜的生长情况及免疫学指标。结果 在第5天时，两组的小肠绒毛高度、隐窝深度、粘膜厚度、全层厚度和粘膜上皮绒毛高度基本相近，而免疫指标实验组明显高于对照组；第8天时，实验组指标全部高于对照组。结论 Gln对感染时大鼠的粘膜有保护作用，可以提高机体免疫力，长期TPN应用Gln效果更为显著。     

苦荞麦总黄酮对高脂血大鼠血脂和抗氧化作用的影响

目的:研究苦荞麸总黄酮对实验性高脂血症大鼠的降脂和抗氧化作用。方法:7w龄,60只Wistar大鼠,按体重随机分为6组;除正常对照组外,其余各组用高脂饲料制作动物高脂血症模型,其中苦荞麸总黄酮分为0.2、0.5、1.0g/kgbw剂量组;以绞股兰总苷片(0.032g/kgbw)为阳性对照组;正常组、模型组为10ml/kgbw蒸馏水,各组每天灌胃一次,连续6w。最终测定血脂、肝脂和抗氧化相关指标。结果:苦荞麸总黄酮各组与模型组比较:各剂量组均能有效地降低血清甘油三酯(TG)、总胆固醇(TC)和肝脏TC、TG值,其中小剂量组降血清TG、抗动脉硬化和抗血清脂质氧化效果显著,不仅使血清TG降低73.9%,TC降低36.4%,还能提高血清谷胱甘肽过氧化物酶(GSH-Px)活性和抗动脉粥样硬化指数(AAI)值,降低致动脉粥样硬化指数(AI)值和血清丙二醛(MDA)含量,且不引起肝脏指数(LI)变化。结论:苦荞麸总黄酮能显著降低大鼠血脂、肝脂水平,提高血清抗氧化酶活性,抑制血清脂质过氧化物产生。     

Effect of lycopene on the vascular endothelial function and expression of inflammatory agents in hyperhomocysteinemic rats

The aim of this study was to investigate the effect of lycopene on the vascular endothelial function and the expression of inflammatory agents in hyperhomocysteinemic rats. Fifty male Sprague-Dawley rats weighed 145- 155g were on a commercial rat chow diet for seven days, and then were randomized into five groups: normal control group (NC) fed with AOAC diet and four hyperhomocysteinemic groups fed with AOAC diet plus 3% L-methionine. Four hyperhomocysteinemic groups were daily supplemented with 0 (HC), 10 mg/kg (HL1), 15 mg/kg (HL2), 20 mg/kg (HL3) lycopene dissolved in corn oil respectively by intragastric administration for 12 weeks. At the end of experiment, their blood and abdominal aortas were collected after etherization. Serum levels of Hcy were determined by HPLC, nitric oxide (NO) and nitric oxide synthase (NOS) by chromatometry, endothelin- 1 (ET-1), vascular cell adhesion molecule-1 (VCAM-1), monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8) by ELISA. Hematoxylin and eosin staining and oil red staining were used to analyze abdominal aortas histologically. Moderate hyperhomocysteinemia was induced in hyperhomocysteinemic groups. Serum level of NO was lower and ET-1 was higher in HC rats than in NC, NL2 and NL3 rats (p<0.01). There was no difference of serum NOS activity among five groups. There were some foam cells and depositions of lipochondria in aortic tunica intima in HC and HL1 rats, which were not found in HL2 and HL3 rats. Serum levels of VCAM-1, MCP-1, IL-8 were higher in HC rats than in NC, NL1, NL2 and NL3 rats (p<0.01). The present study indicated that lycopene exerts an antiatherogenic effect by inhibiting the expression of inflammatory agents in hyperhomocysteninemic rats.     

Predominant conjugation with glycine of biliary and lumen bile acids in rats fed on pectin

1. Bile acids were analysed in the bile and lumen samples of rats which received a cholesterol-free or cholesterol-enriched (5 g/kg) diet free from fibre, or containing cellulose or citrus pectin at the level of 100 g/kg. 2. Dietary pectin but not cellulose increased biliary bile acid concentration and excretion. Dietary cholesterol did not affect biliary bile acids quantitatively. 3. Biliary bile acids were almost exclusively conjugated with glycine or taurine in the various experimental situations. The predominant portion of bile acids in rats fed on the cholesterol-free diet was conjugated with taurine when the diet was either free from fibre or contained cellulose; the ratio of bile acids conjugated with glycine: those conjugated with taurine (G:T) was less than 0.2. In contrast, with pectin as a fibre source, the conjugation with glycine increased enormously (G:T increased to approximately 4). Cholesterol enrichment of the diet also increased the glycine conjugation in all groups of rats. Even in this situation, the G:T was highest in rats fed on pectin. 4. Pectin, but not cellulose, increased the bile acid content of the small intestine and caecum, both in rats fed on the cholesterol-free and cholesterol-enriched diets. Cholesterol feeding doubled the bile acid content of the caecum in rats fed on a fibre-free diet or a cellulose diet, but not in those fed on pectin. No such effect of cholesterol was observed in the small intestine, except for the ileal bile acid content in rats fed on cellulose. 5. A considerable portion of the bile acids in the small intestine was deconjugated. The extent of the deconjugation was higher in the ileum than in the jejunum. As in the bile, G:T in rats fed on pectin (3-5.5) were higher than those in the other groups (0.05-1.05) in various situations. Also, cholesterol feeding considerably increased the ratio in all groups of rats. 6. The observed dietary alteration of the partition of bile acids between glycine and taurine may be of physiological significance in regulating bile acid and lipid metabolism in rats.     

Iridoid extracts from Ajuga iva increase the antioxidant enzyme activities in red blood cells of rats fed a cholesterol-rich diet

The lyophilized aqueous extract of Ajuga iva (Ai) is able to reduce oxidative stress, which may prevent lipid peroxidation in hypercholesterolemic rats. Iridoids (I) were isolated from Ai. We hypothesized that the antioxidant defense status in red blood cells (RBC) and tissues in rats fed a cholesterol-rich diet and treated with Ai may be correlated to these compounds. Male Wistar rats (n = 32) weighing 120 ± 5 g were fed a diet containing 1% cholesterol for 15 days. After this phase, hypercholesterolemic (HC) rats were divided into groups, fed the same diet, and received either the same or different doses (5, 10, or 15 mg/kg body weight by intraperitoneal injection) of I for 15 days. Compared with the HC group, total cholesterol value was 1.4- and 1.2-fold lower in the I₅-HC and I₁₀-HC groups. Serum thiobarbituric acid reactive substance content was 2.3-, 2.9-, and 3-fold lower in the I₅-HC, I₁₀-HC, and I₁₅-HC groups compared with the HC group. In RBC, glutathione peroxidase, glutathione reductase, and superoxide dismutase activities were significantly higher in the I₅-HC, I₁₀-HC, and I₁₅-HC groups than the HC group. Liver, heart, and muscle glutathione peroxidase and superoxide dismutase activities were significantly higher in the groups treated with I than the HC group. Muscle glutathione reductase activity was increased 1.4-fold in the I₅-HC, 1.5-fold in the I₁₀-HC, and 1.5-fold in the I₁₅-HC group. In HC rats, different doses of I increase the antioxidant enzyme activities in RBC and act differently in tissues. Treatment with I may play an important role in suppressing oxidative stress caused by dietary cholesterol and, thus, may be useful for the prevention and/or early treatment of hypercholesterolemia.