高蛋白膳食对限食大鼠肠道抗氧化功能的影响

目的探讨高蛋白膳食对限食大鼠肠抗氧化功能的影响。方法Wistar雄性大鼠,按体重随机分成五组:正常对照组,喂15%酪蛋白合成饲料,自由摄食;限食1和2组分别按正常对照组摄食量的50%和30%对喂15%酪蛋白合成饲料;补蛋白1和2组分别按正常对照组摄食量的50%和30%对喂30%酪蛋白合成饲料。实验2w后处死大鼠,取血和小肠组织进行检测。结果与相应限食组相比,补蛋白组血清SOD以及肠粘膜和肝脏的SOD、GSH-Px活性均有升高的趋势,并且肠粘膜MDA和血清MDA含量显著下降。结论高蛋白膳食能改善机体及肠粘膜的氧化还原状态,减轻自由基的氧化应激损伤,对限食大鼠肠道抗氧化功能有保护作用。     

高蛋白膳食对限食大鼠血清和肠粘膜氨基酸谱的影响

目的探讨高蛋白膳食对限食大鼠血清和肠粘膜氨基酸谱的影响。方法 Wistar雄性大鼠,按体重随机分成五组,分别为正常对照组,喂15%酪蛋白合成饲料,自由摄食;限食1组和2组分别按正常对照组摄食量的50%和30%对喂15%酪蛋白合成饲料;补蛋白1组和2组分别按正常对照组摄食量的50%和30%对喂30%酪蛋白合成饲料。实验2w后处死大鼠,取血和小肠组织检测游离氨基酸含量。结果限食组和补蛋白组的大鼠血清游离氨基酸浓度均低于正常对照组,并且除了甘氨酸和胱氨酸外均有统计学意义(P<0.05),其中苯丙氨酸、酪氨酸、亮氨酸、异亮氨酸、缬氨酸、谷氨酸下降最为明显(P<0.01);而补蛋白组的大鼠血清游离氨基酸浓度又高于相应的限食组,其中苯丙氨酸、酪氨酸、亮氨酸、异亮氨酸、缬氨酸、精氨酸、谷氨酸有显著性差异(P<0.05)。限食组和补蛋白组的大鼠肠粘膜游离氨基酸含量均低于正常对照组,其中苯丙氨酸、酪氨酸、亮氨酸、异亮氨酸、缬氨酸、精氨酸、谷氨酸有显著性差异(P<0.05);而补蛋白组的大鼠肠粘膜游离氨基酸含量又高于相应的限食组,其中亮氨酸、异亮氨酸、缬氨酸、精氨酸、谷氨酸有显著性差异(P<0.05)。结论提高膳食中的蛋白质比例能降低限食对大鼠血清和肠粘膜氨基酸谱的影响,改善血清氨基酸代谢。     

高蛋白膳食对限食大鼠肠免疫功能的保护作用

目的探讨高蛋白膳食对限食大鼠肠免疫功能的保护作用,为高蛋白膳食防治限食引起的肠免疫功能损伤提供理论基础。方法 Wistar雄性大鼠,按体质量随机分成5组,分别为正常对照组(喂15%酪蛋白合成饲料并自由摄食)、限食1组和2组(分别按正常对照组摄食量的50%和30%对喂15%酪蛋白合成饲料);补蛋白1组和2组(分别按正常对照组摄食量的50%和30%对喂30%酪蛋白合成饲料)。实验2周后处死大鼠,取血和小肠组织检测小肠细菌移位率、血清内毒素及肠粘膜中SIgA水平。结果正常对照组未发生细菌移位,补蛋白1组的细菌移位率为25%,显著低于相应的限食1组(50%),差异有显著性(P0.05)。补蛋白1组和2组的血清内毒素水平分别为(283.0±15.1)、(332.5±21.6)EU/L,均显著低于相应的限食组(341.2±29.1)、(434.2±24.3)EU/L,差异有显著性(P0.05),但均显著高于正常对照组(16.3±3.0)EU/L,差异有显著性(P0.01)。补蛋白1、2组肠粘膜SIgA水平均显著高于相应的限食组,差异有显著性(P0.05),但均显著低于正常对照组,差异有显著性(P0.05)。结论提高膳食中的蛋白质比例能增强肠道的免疫功能,减少细菌移位的发生,从而降低肠源性感染的机率。     

高酪蛋白饲料改善不全饥饿大鼠肠粘膜抗氧化的作用

目的研究半饥饿大鼠肠道抗氧化功能的变化及补充蛋白质对其抗氧化功能的改善作用。方法雄性Wistar大鼠40只,按体质量随机分为正常组、50%限食组、70%限食组、50%限食 高酪蛋白组、70%限食 高酪蛋白组。大鼠限食喂养2周后处死取小肠,观察肠粘膜的抗氧化指标变化。结果50%限食 高酪蛋白组大鼠肠粘膜MDA质量浓度〔(16.92±3.89)nmol.g-1〕低于50%限食组MDA〔(23.04±6.52)nmol.g-1〕,接近正常组MDA〔(15.64±4.09)nmol.g-1〕水平;50%限食 高酪蛋白组大鼠肠道超氧化物歧化酶(SOD)的活性〔(317.81±52.63)U.g-1〕明显高于50%限食组大鼠肠道SOD的活性〔(255.22±45.02)U.g-1,P<0.05〕,还原型谷胱甘肽(GSH)浓度〔(360.92±51.96)nmol.g-1〕也高于50%限食组大鼠肠道GSH〔(279.34±36.21)nmol.g-1〕。结论半饥饿状态下增加大鼠饲料中蛋白质比例能提高半饥饿大鼠肠道抗氧化能力,降低MDA浓度。     

膳食蛋白来源对大鼠钙平衡的影响

目的：研究不同来源膳食蛋白质对大鼠尿钙排出的影响。方法：给予SD种Ⅱ级雄性大鼠4种不同蛋白质合成饲料进行观察。结果：谷类蛋白组与酪蛋白组，谷豆混合蛋白组差异有显著性(P＜0．05)；而大豆蛋白组与酪蛋白组和谷豆混合蛋白组差异无显著性(P＜0．05)。即优质蛋白质(大豆和酪蛋白)可减少尿钙排泄。结论：食用谷类食物同时配合食用豆类，可预防缺钙。     

蛋白质对半饥饿大鼠肠黏膜形态的影响

目的:研究半饥饿大鼠肠黏膜形态变化与补充蛋白质对保护肠黏膜的作用. 方法:将24只大鼠随机分为正常对照组、50％正常饲料组、50％饲料+蛋白组.2 周杀死大鼠取小肠,观察肠黏膜形态的变化,测定小肠黏膜超氧化物歧化酶(SOD)、丙二醛(MDA)和DNA含量. 结果:50％饲料+蛋白组大鼠的小肠壁厚度、绒毛高度均好于50％...     

营养

。60729膳食低钙对大鼠生长、代谢的影响—补蛋白和钾或镁的对比实验研究/康德仁…刀营养学报一1995,17(1)一85一88 将104只(雌雄各半)wistar大鼠,按体重和性别分为病区粮偏食组、病粮偏食十J%酪蛋白十0.5%Kcl组、病粮偏食 」%酪蛋白 1%Mgcl:·6H:0组、病粮偏食 1纬caco3组和常规食组。实验结果表明:病粮偏食组、补蛋白补钾组和补蛋白补镁组大鼠体重增长明显低于补ca和常规食组。肝脏组织总蛋白含量病粮偏食组明显低于其余各组。病粮偏食饲料除se舍量低外,ca含量亦低得最突出。病粮偏食组、补蛋白补钾和补蛋白补镁组血浆ca含量仅及常规组…     

临床营养

抗性淀粉干预糖尿病胰岛素抵抗的临床随机对照研究；高蛋白膳食对限食大鼠肠屏障功能的保护作用；降血压肽对人脐静脉内皮细胞eNOS、iNOS、ET-1mRNA表达的影响；NF-κBP65及Bcl-2蛋白在植酸诱导人胃癌细胞凋亡中的作用     

蛋白质对半饥饿大鼠肠黏膜屏障的保护作用

目的:研究大鼠半饥饿状态下肠黏膜屏障的变化与补充蛋白质对其的保护作用. 方法:将48只大鼠随机分为正常对照组、50%正常饲料组、50%正常饲料+蛋白质组.2周后处死大鼠,测定小肠黏膜超氧化物歧化酶(SOD)活性、丙二醛(MDA)、DNA含量,肠系膜淋巴结(MLN)细菌移位率和血清D.木糖水平等. 结果:50%正常饲料+蛋白质组大鼠小肠黏膜DNA含量、SOD活性明显高于50%正常饲料组(P<0.05);血清D-木糖水平和MDA含量明显低于50%正常饲料组(P<0.05).结论:大鼠半饥饿状态下,增加饲料中蛋白质比例,对半饥饿大鼠肠黏膜具有一定的保护作用.     

肠内肠外营养对烧伤大鼠肠粘膜屏障功能的影响及其机制

观察不同营养支持途径对严重烧伤所致肠粘膜屏障功能损害的影响并探讨其机制。采用 30 %体表面积 度烧伤大鼠模型 ,随机分成伤前对照 (C) ,静脉营养 (PN)及肠道营养(EN)组 ,EN和 PN组给予等氮、等热量、等体积的营养液。动态观察了肠粘膜通透性、肠上皮细胞增殖指数、血浆二胺氧化酶 (DAO)活性、肠组织中肠三叶因子 (ITF)含量以及肠粘液层厚度和成分的变化。结果 :烧伤后肠粘膜通透性、血浆DAO活性明显高于伤前 ,而肠上皮细胞增殖指数、ITF含量、肠粘液层厚度及己糖和唾液酸的含量则明显低于伤前。两组相比 EN组大鼠肠粘膜通透性…     

Alteration in skin composition of young rats fed liquid protein diet

The effects of liquid protein diet (LPD) on the collagen metabolism of developing skin tissue was examined in young rats fed a 20% liquid protein diet starting at day 23 after birth. Other rats were pair-fed, but with a 20% casein diet, and another group of rats were fed a 20% casein diet ad libitum. The LPD rats rapidly lost their hair, and they were smaller and weighed less than the pair-fed and ad libitum rats. None of the LPD-fed rats survived beyond day 53 of the study. Collagen contents of the skin continuously increased in all age groups, while hexosamine content decreased from day 23 to 35. From day 23 to 35, noncollagenous protein content in the ad libitum group decreased about 40% and in the LPD and pair-fed groups, about 50%; from day 35 to 48, the decrease was about 35% in the ad libitum group and only about 14% in both the LPD and pair-fed groups. The ratio of Type III to I collagen in the LPD group at days 35 and 48 was greater than that of the ad libitum group. Current observations suggest that LPD alters biochemical composition of the skin on young, growing rats.     

Pyruvate Is Superior to Citrate in Oral Rehydration Solution in the Protection of Intestine via Hypoxia‐Inducible Factor‐1 Activation in Rats With Burn Injury

Background: Recent studies have suggested that pyruvate‐enriched oral rehydration solution (Pyr‐ORS) may be superior to the standard bicarbonate‐based ORS in the protection of intestine from ischemic injury. The aim of this study was to compare the effects of Pyr‐ORS with citrate‐enriched ORS (Cit‐ORS) on the intestinal hypoxia‐inducible factor‐1 (HIF‐1)–erythropoietin (EPO) signaling pathway for enteral rehydration in a rat model of burn injury. Methods: Rats were randomly assigned to 4 groups (N = 20, 2 subgroups each: n = 10): scald sham (group SS), scald with no fluid resuscitation (group SN), scald and resuscitation with enteral Cit‐ORS (group SC), and scald and resuscitation with enteral Pyr‐ORS (group SP). At 2.5 and 4.5 hours after a 35% total body surface area (TBSA) scald, intestinal mucosal blood flow (IMBF), contents of HIF‐1, EPO, endothelial nitric oxide synthase (eNOS), nitric oxide (NO), barrier protein (ZO‐1), levels of serum diamine oxidase (DAO), and intestinal mucosal histology injury score were determined. Results: Serum DAO activities in the scalded groups were significantly elevated, but less raised in group SP than in group SC, at 2.5 hours and at 4.5 hours after the scald. Further, group SP more profoundly preserved intestinal HIF‐1 expression compared with group SC at the 2 time points. Compared with group SC, group SP had markedly elevated intestinal EPO, eNOS, and NO levels at the same time points, respectively (P < .05). Similarly, IMBF and ZO‐1 levels were significantly higher in group SP than in group SC. Intestinal mucosal histopathological scores were statistically higher at 2.5 hours and 4.5 hours after scalding but were more attenuated in group SP than in group SC (P < .05). Immunofluorescence expression of intestinal mucosal ZO‐1 was consistent with the above changes. The above parameters were also significantly different between groups SC and SN (all P < .05). Conclusion: Pyr‐ORS provides a superior option to Cit‐ORS for the preservation of intestinal blood flow and barrier function and the attenuation of histopathological alterations in enteral resuscitation of rats with burn injury. Its underlying mechanism may be closely related to the pyruvate in activation of intestinal HIF‐1‐EPO signaling cascades.     

Characteristics of thyroid function in experimental protein malnutrition.

Two experiments were conducted to study the effects of protein malnutrition on thyroid function. Resting oxygen consumption and serum concentrations of triiodothyronine (T3), thyroxine (T4) and thyroid stimulating hormone (TSH) were measured and correlated with thyroid histology, gain in weight, feed efficiency and carcass energy content in male rats fed isoenergetic diets ad libitum containing 22% (control) or 8% (protein malnourished, PM) casein for 28 or 32 days postweaning. A third group was pair-fed to the PM rats with the control diet. In experiment 2 additional groups were pair-fed to the PM rats with 8% casein diets in which the casein was substituted with different mixtures of carbohydrate and fat. Resting oxygen consumption/body weight (0.75) decreased as body weights increased in all groups, but was consistently greatest in PM rats. In PM rats, plasma T3 was 130% of controls after 11 days of the dietary regimen and averaged 215% of controls from days 18 through 32. In experiment 2 both T3 and T4 concentrations were approximately twice controls in all PM groups. TSH concentrations were within the normal range in all groups throughout. Feed efficiency averaged 36 to 40% of controls and mean weight gain was 30 g after 28 days in the PM groups, compared to 114 and 91 g, respectively, in the pair-fed control rats. Carcass energy content of PM rats after 28 days was significantly lower than in control or pair-fed control rats. Thyroid morphology was compatible with increased secretory activity in all the protein-malnourished groups, compared with normal activity in the control and pair-fed control groups. Thermogenesis, as measured by oxygen consumption, was markedly increased in the PM rats compared to controls. These observations are consistent with a diet-induced thermogenesis in the protein-malnourished rats. In contrast to simple under-nutrition where energy expenditure may be conserved by decreases in thyroid function and thermogenesis, increases in thyroid function and thermogenesis in protein malnutrition could provide an energy balancing mechanism whereby unneeded non-protein energy in the diet could be dissipated as heat, and survival enhanced.     

β-胡萝卜素对急性放射损伤大鼠小肠黏膜结构和屏障功能的影响

目的: 探讨β-胡萝卜素(β-C)对大鼠急性放射性损伤小肠黏膜结构和屏障功能保护作用的影响. 方法: 将40只大鼠随机分为四组,即对照组(C组)、单纯照射组(R组)、β-C 5 mg/(kg·d)组(T1组)和β-C 10 mg/(kg·d)组(T2组).连续灌胃14 d后,R组、T1组、T2组用直线加速器,以9 Gy剂量进行全腹一次性照射,第4天处死大鼠,测定血浆二胺氧化酶(DAO)活性和内毒素浓度,留取空肠组织,观察肠黏膜形态,测定绒毛隐窝轴(CVA)长度. 结果: R组大鼠体质量增长缓慢,CVA明显短于C组(P<0.01),肠黏膜损伤严重(P<0.008 3);血浆内毒素浓度较C组显著升高(P<0.01),两组间DAO活性无显著性差异.T1组大鼠CVA明显长于R组(P<0.01),肠黏膜损伤轻于R组(P<0.008 3);血浆内毒素浓度较R组明显降低(P<0.01);两组间DAO活性无显著性差异(P>0.05).T2组大鼠体质量较T1组显著增长(P<0.01),CVA明显长于T1组(P<0.01),肠黏膜损伤轻于T1组(P<0.008 3);血浆内毒素浓度较T1组明显降低(P<0.01);DAO活性无显著性差异(P>0.05). 结论: 补充10 mg/(kg·d)β-C可减轻X线照射引起的大鼠小肠黏膜损伤,对维持黏膜屏障功能有一定的保护作用.     

Favorable effects of egg white protein on lipid metabolism in rats and mice

Egg is a cholesterol-rich food and has a strong hyper-cholesterolemic action. However, all the cholesterol is in egg yolk and egg white is cholesterol-free. The effect of egg white protein and its hydrolysates on the serum lipids were compared with casein and soybean protein in rats and mice. The animals were given 30% casein diet (Ca group) or diets of 15% casein plus 15% soybean protein isolate (SPI group), egg white protein (EW group) or egg white protein hydrolysates (EW-P group) for 3 (rats) or 2 (mice) weeks. Food intake and growth were very similar among the different dietary groups. Hypocholesterolemic effect was observed in SP, EW and EW-P groups in rats and EW group in mice. Prevention of the reduction of HDL-cholesterol was found in EW and EW-P groups in rats and EW-P group in mice. The result suggests the possibility of the use of egg white for the prevention and treatment of hyper-cholesteremia.