食物蛋白质对量幼鼠脑核酸,蛋白质含量和超微结构的影响

本文研究了不同来源食物蛋白质对出生５及２６日龄Ｗｉｓｔａｒ大鼠脑ＤＮＡ，ＲＮＡ和蛋白质含量及脑超微结构的影响。结果表明，全蛋，鱼肉及补充蛋氨酸和牛磺酸后的大豆３者间，脑ＤＮＡ，ＲＮＡ和蛋白质含量无显著性差异（Ｐ＞０．０５），全谷组则均显著低于其它各组（Ｐ＜０．０５）。相关分析表明，食物蛋白质氨基酸评分与脑ＤＮＡ含量呈正相关（Ｐ＜０．０５）。透射电镜下观察到全谷组大脑皮质及海马区有神经元固缩，核锯齿     

高温与电离辐射对胎鼠脑核酸,蛋白质的影响

为探索高温和电离辐射对胎脑的影响，用孕第９天小鼠给予４２℃和１．０Ｇｙ处理，孕第１８天取胎脑，测量ＤＮＡ、ＲＮＡ和蛋白质含量。结果表明，１．０Ｇｙ照射组、照射＋４２℃组对照组比，胎脑核酸和蛋白质有明显减少。４２℃＋照射组与４２℃组比，胎鼠脑核酸和蛋白质含量没有显著性变化。提示辐射可引起胎脑核酸、蛋白质含量减少，预先４２℃１０分钟处理孕鼠，随后再经较大剂量电离辐射的照射，胎仔表现出交叉适应性反应。     

食物蛋白质对幼鼠脑部分神经递质代谢及组织学的影响

用五种不同来源食物蛋白质喂饲健康、纯种Ｗｉｓｔａｒ母鼠，观察其对出生５及２６日幼鼠脑蛋白质和５－羟色胺含量、乙酰胆碱酯酶的活性及脑组织的影响。结果表明：两个发育阶段仔鼠脑均受到食物蛋白质质量的影响，并以２６日龄幼鼠表现更为明显；全蛋、鱼肉及补充蛋氨酸和牛磺酸大豆三组间，脑蛋白质含量、乙酰胆碱酯酶的活性无显著性差异（Ｐ＞０．０５）；全谷组除５－ＨＴ含量高外，其余各项指标均低于其它各组；食物蛋白质氨基酸评分与乙酰胆碱酯酶活性相关分析表明，二者呈高度正相关（Ｐ＜０．００１）；透射电镜下，全谷组仔鼠大脑皮质、海马区部分神经元变性，有暗细胞形成，神经突触膜增厚、间隙丝状物融合，神经毡区水肿。提示，经补充蛋氨酸和牛磺酸的大豆、全蛋和鱼肉为有利于早期脑发育的良好食物蛋白质来源。     

蛋白质对脑发育及脑功能的影响

本文着重介绍脑蛋白质代谢的特点，蛋白质不同营养水平与脑发育及脑功能的关系，以及影响脑中神经递质的水平，起到调节脑功能的作用。     

163 蛋白质对脑发育及脑功能的影响

本文着重介绍脑蛋白质代谢的特点，蛋白质不同营养水平与脑发育及脑功能的关系，以及影响脑中神经递质的水平，起到调节脑功能的作用。     

蛋白质水平对大鼠子代脑发育及功能的影响

孕前、妊娠期及哺乳期给予雌性Ｗｉｓｔａｒ大鼠含酪蛋白分别为４０％、２０％和８％的等能量饲料，观察对子代脑发育及脑功能的影响。结果表明，２０％酪蛋白营养水平不能充分满足哺乳期幼鼠脑生长发育的需要。妊娠及哺乳期严重的营养不良对脑发育所产生的损害，断乳后即使给予蛋白质补充，也未能使脑发育得到恢复。     

食物蛋白质对幼鼠中央杏仁核生长抑制素神经元发育的影响

采用光镜免疫组织化学结合计算机图像定量分析研究了３种食物蛋白质对幼鼠中央杏仁核生长抑制素（ＳＯＭ）神经元生长发育的作用．结果表明：全蛋、鱼肉蛋白组幼鼠中央杏仁核ＳＯＭ神经元单位体积粒子密度和胞体和面积均明显高于全谷组（Ｐ＜０．０５），而细胞灰度值则以全谷组为高（Ｐ＜０．０５），显示了动物蛋白质在体内有很强的促进幼鼠脑神经元生长发育的作用；从形态学角度为研究优质蛋白质促进脑生长作用机理提供了证据．     

二甲亚砜对人表皮的核酸和蛋白质合成的影响

用体外培养的人的伪表皮作为模型，进行药物毒理学作用的研究，观察了二甲亚砜（ＤＭＳＯ）在不同浓度和不同接触时间条件下，对人的伪表皮细胞脱氧核糖核酸（ＤＮＡ）、核糖核酸（ＲＮＡ）和蛋白质合成的影响：随着接触时间的延长，ＤＮＡ、ＲＮＡ和蛋白质合成均受抑制。低浓度条件下（１％），ＤＮＡ、ＲＮＡ和蛋白质合成增加；在１５～５０％浓度下，ＤＮＡ和蛋白质合成抑制，而ＲＮＡ合成仍增加；在高浓度条件下（７０％～１００％），ＤＮＡ、ＲＮＡ和蛋白质合成均明显抑制。     

蛋白质水平对大鼠胚胎期脑发育的影响

成年雌性Ｗｉｓｔａｒ大鼠３０只，体重２４０±２６．５ｇ，等分为Ⅰ、Ⅱ、Ⅲ３个组。各组蛋白质分别占饲料的４０％，２０％和８％。饲养４３天（受孕前２１天），观察饲料中蛋白质水平对胚胎期大鼠脑发育的影响。结果表明，新生幼鼠体重和脑重，Ⅰ组最重，分别为６．９５ｇ和２４０．９ｍｇ；Ⅱ组次之，分别为６．５７ｇ和２３７．８ｍｇ，Ⅲ组最轻，分别为５．６２ｇ和２１０．９ｍｇ。各组间体重均有显著差别（Ｐ＜０．０１），Ⅲ组脑重明显低于Ⅰ、Ⅱ组（Ｐ＜０．０１）。各组脑中蛋白质含量依次为１０．０３ｍｇ、９．０９ｍｇ和７．４６ｍｇ（Ｐ＜０．０１或＜０．０５），脑中ＤＮＡ和ＲＮＡ水平以及每ｇ脑组织中ＲＮＡ含量也是Ⅰ组最高，Ⅲ组明显低于其它两组。说明蛋白质水平不同对大鼠胚胎期脑生长发育有一定影响。     

科学选用蛋白质食物

富含蛋白质的食物形形色色．各有优劣之分，如何吃才能获得最好的保健效果呢？     

Effect of Adding Dietary Methionine to a Low Soy Protein Diet on the Brain Protein Synthesis Rate in Ovariectomized Female Rats

Abstract

A deficiency of sex hormones affects brain function in mammals, including the decrease of protein synthesis. Recently, we have shown that the protein synthesis in the brain depended on the quality of dietary protein in ovariectomized female rats. The methionine is the first limiting amino acid for the recommended dietary allowance of amino acids in soy protein. The purpose of this study was to determine whether the addition of dietary methionine affected the rate of brain protein synthesis in ovariectomized female rats fed on the soy protein diet. Experiments were conducted on two groups of ovariectomized female rats (24 week) given the diets containing 5% soy protein or 5% soy protein+0.2% methionine for 10 d. The fractional rates of protein synthesis in cerebral cortex and cerebellum significantly increased with an addition of dietary methionine. In the brain, the RNA activity [g protein synthesized/((g RNA)· d)] was significantly correlated with the fractional rate of protein synthesis. The RNA concentration (mg of RNA/g of protein) was not related to the fractional rate of protein synthesis in any organ. The results suggest that the addition of limiting amino acid for the low soy protein elevates the rate of protein synthesis in the brain of ovariectomized female rats, and that RNA activity is at least partly related to the fractional rate of brain protein synthesis.     

Effects of High Dietary Protein on Coping Behavior,Memory Performance,and Sensory Discrimination in Rats

Rats consuming a high-protein diet (HP; 50% casein) have increased locomotor activity, are hyper-responsive to nociceptive stimuli, and have increased basal arousal levels, as compared to rats maintained on a normal-protein diet (NP; 20% casein). The present study was performed to determine whether animals on the HP diet display deficits in learning, memory, and sensory discrimination. Male, Sprague-Dawley rats (4 months old) were divided into two groups and fed either the NP diet or the HP diet, ad libitum, for 32 weeks. Then the animals were observed in a variety of behavioral tests. In the swimming cylinder of Porsolt, which tests adaptation to stress, the HP group was significantly less able than the control group to develop an effective coping strategy (p < 0.05). When tested in the Morris Watermaze, animals on both diets performed equally well in the acquisition and recall of spatial information. During the recording of auditory evoked responses to deviant tones, short-term auditory memory traces degraded more quickly in the HP group than in the NP group (p < 0.05). These data suggest that rats fed the HP diet experienced deficits in short-term memory, associated with a diminished ability to cope with acute stress, whereas long-term memory was unaffected.     

Dietary Protein and Central Monoamine Concentrations in the Rat

In a previous report we demonstrated that rats that consumed a high-protein diet (HP; 50% casein) for 36 weeks were hyperactive and hyperresponsive to nociceptive stimuli, compared to rats that consumed normal (NP; 20% casein) or low-protein (LP; 8% casein) diets. In addition, we have also previously, reported that dopamine concentrations in the nigrostriatal system of the rats were decreased and increased, respectively, with a decrease and increase in dietary protein. In the present study, rats were maintained on the HP, NP and LP diets and regional changes in the concentrations of norepinephrine (NE) and serotonin (5-hydroxytryptamine, 5-HT) were assessed. Concentrations of 5-HT in the medial raphe, dorsal raphe, and several of their target tissues, revealed no consistent effect of manipulating dietary protein over the range of 5-HT levels measured. NE concentrations in most of the brain regions innervated by neurons of the locus coeruleus and lateral tegmentum showed no significant differences among the diet groups. However, NE concentrations in the parietal cortex were significantly increased in rats that consumed the HP diet. The present study indicates that the brain NE pathways, particularly that innervating the parietal cortex, is susceptible to dietary protein manipulation.     

苯致小鼠淋巴细胞DNA、RNA损伤作用

目的研究苯对小鼠淋巴细胞DNA、RNA损伤作用。方法采用单细胞凝胶电泳方法和3H-胸腺嘧啶1、4C-尿嘧啶掺入技术检测不同剂量苯[100,200,400 mg/(kg.bw)]经腹腔注射染毒对小鼠外周血、脾脏、胸腺淋巴细胞DNA、RNA损伤情况。结果除了苯染毒为100 mg/(kg.bw)剂量组外,小鼠外周血淋巴细胞DNA彗星细胞率、彗星尾长均高于阴性对照组(P<0.05),3H-胸腺嘧啶和14C-尿嘧啶掺入计数每分钟衰变数(dpm)值明显低于阴性对照组(P<0.01)。结论苯可致外周血淋巴细胞DNA损伤,明显影响小鼠脾脏、胸腺淋巴细胞DNA和RNA合成而产生遗传毒性作用。     

Digitally Supported Dietary Protein Counseling Changes Dietary Protein Intake,Sources, and Distribution in Community-Dwelling Older Adults

Digitally supported dietary counselling may be helpful in increasing the protein intake in combined exercise and nutritional interventions in community-dwelling older adults. To study the effect of this approach, 212 older adults (72.2 ± 6.3 years) were randomised in three groups: control, exercise, or exercise plus dietary counselling. The dietary counselling during the 6-month intervention was a blended approach of face-to-face contacts and videoconferencing, and it was discontinued for a 6-month follow-up. Dietary protein intake, sources, product groups, resulting amino acid intake, and intake per eating occasion were assessed by a 3-day dietary record. The dietary counselling group was able to increase the protein intake by 32% at 6 months, and the intake remained 16% increased at 12 months. Protein intake mainly consisted of animal protein sources: dairy products, followed by fish and meat. This resulted in significantly more intake of essential amino acids, including leucine. The protein intake was distributed evenly over the day, resulting in more meals that reached the protein and leucine targets. Digitally supported dietary counselling was effective in increasing protein intake both per meal and per day in a lifestyle intervention in community-dwelling older adults. This was predominantly achieved by consuming more animal protein sources, particularly dairy products, and especially during breakfast and lunch.     

Associations Between the Dietary Inflammatory Index,Brain Volume,Small Vessel Disease,and Global Cognitive Function

BackgroundAn inflammatory diet is related to poorer cognition, but the underlying brain pathways are unknown.ObjectiveThe aim of this study was to examine associations between the Energy-Adjusted Dietary Inflammatory Index (E-DII) and brain volume, small vessel disease, and cognition in people with and without type 2 diabetes mellitus (T2DM).DesignThis is a secondary cross-sectional analysis of data from the Cognition and Diabetes in Older Tasmanians study.Participants/settingsThis study included 641 participants (n = 326 with T2DM) enrolled between 2005 and 2011 from Tasmania, Australia.Main outcome measuresThe E-DII was computed from the 80-item Dietary Questionnaire for Epidemiological Studies, version 2. Brain volumes (gray matter, white matter, and white matter hyperintensities), infarcts, and microbleeds were obtained from magnetic resonance imaging. Global cognition was derived from a comprehensive battery of neuropsychological tests.Statistical analysisLogistic and linear regressions were performed to examine associations between E-DII and brain measures and a global cognitive score, adjusting for demographics, energy, T2DM, mood, ambulatory activity, and cardiovascular risk factors. An E-DII × T2DM interaction term was tested in each model.ResultsThe mean (standard deviation) age of participants was 69.8 (7.4) years. There were no associations between the E-DII and any of the brain structural measures or global cognitive function in fully adjusted models. There was a modification effect for T2DM on the association between E-DII and gray matter volume (T2DM: β = 1.38, 95% CI –3.03 to 5.79; without T2DM: β = –4.34, 95% CI, –8.52 to –0.16), but not with any of the other outcome measures.ConclusionsIn this cross-sectional study, E-DII was not associated with brain structure or global cognition. In 1 of the 7 outcomes, a significant modification effect for T2DM was found for the associations between E-DII and gray matter. Future prospective studies are needed to clarify the associations between diet-related inflammation and brain health.     

Diet-Induced Weight Loss: The Effect of Dietary Protein on Bone

High-protein (>30% of energy from protein or >1.2 g/kg/day) and moderately high-protein (22% to 29% of energy from protein or 1.0 to 1.2 g/kg/day) diets are popular for weight loss, but the effect of dietary protein on bone during weight loss is not well understood. Protein may help preserve bone mass during weight loss by stimulating insulin-like growth factor 1, a potent bone anabolism stimulator, and increasing intestinal calcium absorption. Protein-induced acidity is considered to have minimal effect on bone resorption in adults with normal kidney function. Both the quantity and predominant source of protein influence changes in bone with diet-induced weight loss. Higher-protein, high-dairy diets may help attenuate bone loss during weight loss.     

邯郸市居民膳食摄入及膳食结构状况分析

目的了解邯郸市居民膳食摄入及膳食结构状况,为指导当地居民合理膳食,提高营养水平和促进健康提供科学依据。方法采用多阶段分层与人口成比例的整群随机抽样方法,以家庭为单位进行入户调查,利用3d24h膳食回顾和3d全家称重数据,用Excel建立数据库,用SPSS17.0统计软件进行数据分析。结果邯郸市居民膳食摄入以谷类为主,平均标准人日谷类食物摄入量440.9g,水果摄入量34.9g,奶及其制品摄入量52.6g,食用油、盐平均摄入量分别为43.2和11.7g。每标准人日摄入能量为8369.2kJ,蛋白质标准人日摄入量为60.9g;脂肪为85.5g,膳食纤维为11.4g。谷类食物提供的能量占总能量的47.8%,来源于脂肪提供的能量比例为37.9%。结论邯郸市居民膳食摄入以谷类为主,蔬菜和水果摄入明显不足,油、盐摄入相对较高,脂肪摄入高于全国水平,脂肪供能比超出建议范围,膳食结构不合理。相关部门应加强宣传与干预,倡导正确的平衡膳食理念。     

核酸对铅致大鼠氧化应激的影响

目的:研究核酸营养对大鼠外周血淋巴细胞DNA损伤的影响。方法:大鼠灌胃饮食核酸5周后,采用单细胞凝胶电泳技术对外周血淋巴细胞DNA损伤进行分析。结果:核酸组大鼠淋巴细胞DNA的迁移率和尾长均显著低于对照组(P<0.05)。结论:饮食核酸对淋巴细胞DNA损伤具有一定的保护作用。