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1.
Through gas-liquid chromatography it can be shown that increasing the ingestion of linoleic acid-containing fats increases the deposition of linoleic acid in erythrocytes and in brain tissue. Such changes are probably causally related to the tocopherol requirement, the incidence of chick encephalomalacia, and the peroxide hemolysis test. Whether similar mechanisms are involved in the ability of unsaturated oils to lower serum cholesterol levels remains to be determined.  相似文献   

2.
Selective phospholipid adsorption and atherosclerosis   总被引:1,自引:0,他引:1  
Disaturated (fully saturated) lecithins adsorb onto solid surfaces more readily than lecithins in which one or both fatty acids are unsaturated. If saturated lecithins adsorb to arterial walls as they do to glass and polystyrene surfaces, there may be increased probability of atherosclerosis when the disaturated lecithin content of plasma is elevated. Analyses of lecithins in plasma samples from patients with myocardial infarction, and from patients with premature atherosclerosis but with low concentrations of plasma cholesterol and triglycerides, are consistent with the hypothesis that a high concentration of disaturated lecithin in plasma may be a significant risk factor for atherosclerosis, independent of triglyceride and cholesterol concentrations.  相似文献   

3.
Blockade of gamma-aminobutyric acid receptor function by direct microinjection of bicuculline into the nucleus ambiguous in cats produced a marked increase in gastric motility which was mediated by the vagus nerve. This effect was reversed by muscimol. These data indicate that the nucleus ambiguous may be an important brain site influencing gastric function and that the neurotransmitter controlling parasympathetic overflow from this nucleus to the stomach is gamma-aminobutyric acid.  相似文献   

4.
以鲣鱼脑为原料,对鱼脑磷脂超声提取方法进行了研究.以磷脂提取率为评价指标,通过单因素和正交试验优化了鱼脑磷脂提取的条件.结果表明:以正己烷-乙醇(体积比2∶1)为提取溶剂,超声提取时间为40 min,超声温度为35℃,固液比为1∶9 (g∶ mL),超声提取2次,在此条件下鱼脑磷脂的提取率达到氯仿-甲醇法的87.1%;通过薄层色谱分析,确定鲣鱼脑磷脂中含有磷脂酰乙醇胺、磷脂酰胆碱和神经鞘磷脂3种磷脂;用气相色谱法测定鲣鱼脑磷脂的脂肪酸组成,高不饱和脂肪酸中DHA和EPA的含量分别为21.1%和2.4%.研究表明,用超声法提取鱼脑磷脂具有可行性,鱼脑磷脂中含丰富的不饱和脂肪酸,在食品加工中具有一定的应用前景.  相似文献   

5.
用辣根过氧化物酶法研究了4只仔猪大脑皮质十字前回和后回传入神经的来源,将HRP注入十字前回,在蓝斑,中缝背核,中脑中央灰质,丘脑背内侧核,腹前核,腹外侧核和板内核,十字前回和薛氏回等诸多结构内出现标记细胞。将HRP注入十字后回,在蓝斑,中脑中央灰质,中缝背核,丘脑外侧核群,背内侧核,板内核,十字前回和后回,冠状回和扣带回等处出现标记细胞,结果表明,此二回均接受广泛的传入纤维,在丘脑皮质联系中,十字  相似文献   

6.
A method employing the use of ion-exchange resin beads is described for the punctate introduction of discrete amounts of various anions, cations, or zwitterions into given brain regions. A series of experiments utilizing the method to introduce ionic copper into the caudate nucleus with the resulting motor manifestations are discussed.  相似文献   

7.
The central auditory system translates sound localization cues into a map of space guided, in part, by visual experience. In barn owls, this process takes place in the external nucleus of the inferior colliculus (ICX). However, to date, no trace of visual activity has been observed in this auditory nucleus. Here we show that strong visual responses, which are appropriate to guide auditory plasticity, appear in the ICX when inhibition is blocked in the optic tectum. Thus, visual spatial information is gated into the auditory system by an inhibitory mechanism that operates at a higher level in the brain.  相似文献   

8.
ω-3不饱和脂肪酸的生物学作用   总被引:6,自引:1,他引:6  
由于人们的膳食中饱和脂肪酸 /多不饱和脂肪酸 (S/P)及 ω- 6不饱和脂肪酸 /ω- 3不饱和脂肪酸的比例失调 ,使得心血管的发病率显著增加。正因为 ω- 3不饱和脂肪酸的摄入量相对不足 ,所以人们更加重视ω- 3不饱和脂肪酸在脂肪酸促进胎儿和新生儿的大脑发育 ,抗肿瘤和炎性反应及降低冠心病、高血压、动脉粥样硬化、二型糖尿病等发病率的特殊作用 ,这些作用源于ω- 3的某些生物学作用。本文阐述 ω- 3功能活性的生物学作用基础  相似文献   

9.
Selective sparing of a class of striatal neurons in Huntington's disease   总被引:29,自引:0,他引:29  
A distinct subpopulation of striatal aspiny neurons, containing the enzyme nicotinamide adenine dinucleotide phosphate diaphorase, is preserved in the caudate nucleus in Huntington's disease. Biochemical assays confirmed a significant increase in the activity of this enzyme in both the caudate nucleus and putamen in postmortem brain tissue from patients with this disease. The resistance of these neurons suggests that the gene defect in Huntington's disease may be modifiable by the local biochemical environment. This finding may provide insight into the nature of the genetically programmed cell death that is a characteristic of the disease.  相似文献   

10.
在脊髓的颈中部、颈膨大部和腰膨大部单侧注射或包埋HRP(辣根过氧化物酶),逆行追踪了28例北京鸭,对中脑至脊髓的传导通路的起始部位、细胞构筑和机能进行了系统的研究。发现大量标记细胞分布在中脑对侧的红核,双测的Cajal中介核、中央灰质和动眼神经副交感核(即EW核)内。此外,还发现少量标记细胞分布在中脑中缝核和双侧的中脑外侧网状结构。而在顶盖内,没有任何部位出现标记细胞。研究结果表明,北京鸭除具有红核脊髓束外,还存在着Cajal中介核至脊髓的直接传导通路,EW核至脊髓的直接传导通路以及中缝核和网状结构至脊髓的直接传导通路,而不存在与哺乳类相似的顶盖脊髓束。  相似文献   

11.
Distinct monoamine oxidase A and B populations in primate brain   总被引:22,自引:0,他引:22  
Monoclonal antibodies specific for monoamine oxidase (MAO) A and MAO B, respectively, were used to localize these enzymes in primate brain. The reagents recognized different populations of neurons: those that recognized MAO A were located in cell groups containing catecholamines, including the substantia nigra, nucleus locus coeruleus, nucleus subcoeruleus, and the periventricular region of the hypothalamus, whereas those that recognized MAO B were observed in serotonin regions, including the nucleus raphe dorsalis and nucleus centralis superior. These data illustrate the physiological independence of MAO A and B and show that neurons may be specialized for their degradative as well as their synthetic functions.  相似文献   

12.
The injection of epinephrine into the third ventricle of the rat brain causes a biphasic elevation and depression in the integrated multiple-unit electrical activity of the median eminence. Activity in the arcuate nucleus decreases after the injection of the catecholamines. These changes in the integrated multiple-unit electrical activity may be related to the secretion of hormones by the anterior pituitary gland.  相似文献   

13.
Fetal raphe cells transplanted into the hypothalamus reversed facilitation of feminine sexual behavior in rats with brain lesions induced by 5,7-dihydroxytryptamine. Immunocytochemical and chemical analyses of serotonin indicate that reinnervation of the ventromedial nucleus of the hypothalamus by the transplants is associated with behavioral recovery. The findings suggest that transplanted fetal tissue can exert functional regulation over an innate, complex, hormone-dependent behavior in adult rats.  相似文献   

14.
山绿茶总黄酮对小鼠高脂血症模型调脂作用的研究   总被引:1,自引:1,他引:0  
取ICR小鼠,饲喂高脂饲料,以建立高脂血症动物模型,用山绿茶总黄酮[300、150、75 mg·(kg·d)~(-1)]连续灌胃小鼠28 d,检测模型小鼠血清甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白(LDL-C)、高密度脂蛋白(HDL-C);取肝脏制作切片,观察组织结构.结果表明:高脂血症模型小鼠的TC、TG、LDL C含量明显高于正常组,HDL-C含量低于正常组;肝细胞中充满大量脂肪颗粒,细胞核呈固缩状.与模型组相比,山绿茶总黄酮高、中剂量均能一定程度降低血清LDL-C含量、提高HDL含量,差异极显著;山绿茶总黄酮能减少肝细胞质中脂肪颗粒及炎性细胞;部分细胞核无固缩现象,较模型组其形态结构有所改善.说明山绿茶总黄酬在一定程度上可降低高脂血症模型小鼠LDL-C含量、提高HDL含量,对血脂水平有调节作用;可改善肝细胞脂肪变性的形态结构.  相似文献   

15.
利用10只北京鸭脑制成的连续切片,经Nissl,Luxol固兰-克紫法染色,光镜观察中脑丘及其内部的神经核团的形态及细胞构筑,结果表明:北京鸭的中脑丘分为13个小层次,总体划成5个大层;峡核由大细胞部和小细胞部构成,且小细胞部的细胞组成有很大差异;半圆丘结构及半月状核与其它禽类相似。  相似文献   

16.
Apolipoprotein E is a plasma protein that serves as a ligand for low density lipoprotein receptors and, through its interaction with these receptors, participates in the transport of cholesterol and other lipids among various cells of the body. A mutant form of apolipoprotein E that is defective in binding to low density lipoprotein receptors is associated with familial type III hyperlipoproteinemia, a genetic disorder characterized by elevated plasma cholesterol levels and accelerated coronary artery disease. Apolipoprotein E is synthesized in various organs, including liver, brain, spleen, and kidney, and is present in high concentrations in interstitial fluid, where it appears to participate in cholesterol redistribution from cells with excess cholesterol to those requiring cholesterol. Apolipo-protein E also appears to be involved in the repair response to tissue injury; for example, markedly increased amounts of apolipoprotein E are found at sites of peripheral nerve injury and regeneration. Other functions of apolipoprotein E, unrelated to lipid transport, are becoming known, including immunoregulation and modulation of cell growth and differentiation.  相似文献   

17.
In our studies on the entry of drugs into the central nervous system we have found the technique of autoradiography combined with radioassay to be a valuable research tool. It has disclosed such unsuspected phenomena as the dual routes of entry into the brain of acetazolamide. Although many factors controlling drug entry remain to be studied, we propose certain general conclusions. 1) The anatomical boundaries of brain are clearly reflected by the penetration and accumulation of all compounds we have studied-a finding that confirms the original proposition that whole-brain homogenates are inadequate for the study of drug and brain relationships. 2) Circulation, expressed as egional blood flow or volume of capillary blood, was seldom decisive in nfluencing entry or accumulation of exogenous substances in the brain. To date, the only compounds demonstrated to be circulation-dependent are trifluoroiodomethane and thiopental. Both are extremely fat-soluble. Tissue binding appears to be an additional factor in the case of thiopental. 3) Penetration is retarded by myelin. All substances we have studied have shown a relatively slower rate of entry into this tissue. In immature brain, before myelinization has taken lace, the primordial white matter is readily penetrated. We have suggested that entry into mature white matter is retarded by the lamellated membranes of the myelin sheath, which should be regarded, therefore, as a component of the blood-brain barrier. The small interstitial space indicated by the limited entry of sulfate ion is an additional hindrance to dispersal of exogenous substances into brain parenchyma. The blood-brain barrier is a complex anatomical, physiological, and biochemical phenomenon, and no unitary hypothesis is adequate to embrace all the observed events. 4) Accumulation of a drug in the brain implies some form of binding or interaction between drug and tissue. Findings on injection of phenobarbital, thiopental, or diphenylhydantoin illustrate such an accumulation. These binding interactions may be nonspecific, as is probable in the case of drugs bound to plasma protein. However, a more fundamental significance is suggested when a drug is found to bind, react with, or accumulate in, a specific anatomical structure of the brain. We have made reference to this possibility in connection with the localization of isonicotinic acid hydrazide or its metabolites in the hippocampus (46), and we have also reported the striking accumulation of acetazolamide in hippocampus, caudate nucleus, and hypothalamus. Although the binding process is poorly understood, further investigation of these phenomena should lead to a clearer understanding of regional variations in brain chemistry. While one should not assume that the demonstration of a focal concentration of a drug implies site of action, correlation between pharmacological action, electrophysiological events, biochemical changes, and temporal and regional drug concentrations may indeed exist (47).  相似文献   

18.
通过建立数学模型并将其编制成计算机软件的方法,方便快捷地求解各种原料油在脂肪酸配比合理的调和油中所占的份额,在同一产品中同时满足了MUFA:PUFA=1∶1和PUFA中n-6∶n-3=4~6∶1的脂肪酸配比要求,并能调配出成本最低和风味最浓的产品。  相似文献   

19.
The neural integrator, which converts eye velocity signals into position signals, is central to oculomotor theory. Similar integrators are probably necessary in any neural system that changes and maintains muscular tension. The integrator for horizontal eye position is in the pons, but the locations of the vertical and torsional integrators have not been clearly defined. Recording three-dimensional eye movements in alert monkeys during microstimulation and pharmacological inactivation of midbrain sites showed that the interstitial nucleus of Cajal generates both the torsional and vertical eye position signals. Up and down signals are linked with clockwise signals in the right brain and counterclockwise signals in the left brain. This three-dimensional coordinate system achieves orthogonality and bilateral symmetry without redundancy and optimizes energy efficiency for horizontal visual scanning.  相似文献   

20.
兔脑和脊髓内开胃素A免疫阳性神经元和神经纤维的分布   总被引:1,自引:1,他引:0  
采用免疫组织化学法研究了10只青紫蓝兔脑内开胃素(Orexin) A免疫阳性神经元和神经纤维的分布。结果显示,Orexin A免疫阳性神经元分布于下丘脑的视上核、室旁核、背内侧核、穹隆周核、外侧区、前区和后区以及底丘脑的未定带。Orexin A免疫阳性神经纤维广泛分布于中枢神经系统内,在端脑分布于大脑皮质、尾状核、隔核和杏仁核;在间脑分布于丘脑、下丘脑、上丘脑和垂体;在中脑分布于中央灰质、前丘、后丘、黑质、网状结构和中缝核;在脑桥分布于蓝斑、网状结构和中缝核;在延髓分布于极后区、孤束核和迷走神经背侧运动核;在小脑和脊髓也有分布。  相似文献   

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