三个柠檬品种果实非可食部分初生代谢产物分析

为了比较贵州产尤力克柠檬、四季柠檬和阿特摩柠檬果实非可食部分初生代谢产物差异,本研究采用GC-MS分析了3个柠檬成熟果实非可食部分氨基酸、有机酸和糖等初生代谢产物含量。结果表明,共检测到29个初生代谢产物,其中氨基酸8个、有机酸11个、糖10个,不同柑橘品种不同组织氨基酸、有机酸、糖等初生代谢产物种类和含量存在较大的差异。3个品种均是脯氨酸含量最高;3个品种有机酸种类相似,黄皮层和白皮层含量最高的为奎宁酸,而囊衣含量最高的为柠檬酸。对检测的糖类而言,均是葡萄糖含量最高。     

仔猪小肠对二肽吸收特点的研究

本试验采用体外外翻肠囊的方法研究了等摩尔浓度的Ｌ 甘氨酸 Ｌ赖氨酸组成的二肽（Ｇｌｙ－Ｌｙｓ）和游离甘氨酸和赖氨酸混合物（Ｇｌｙ＋Ｌｙｓ）在仔猪小肠各段的吸收特点。将仔猪小肠划分为空肠前段、中段、后段和回肠段,分别在各段设置了两个不同的培养液处理组,分别是浓度为２０ｍｍｏｌ／Ｌ的Ｇｌｙ－Ｌｙｓ和Ｇｌｙ＋Ｌｙｓ混合物培养液组。每个处理３个重复（回肠段无重复）,每个重复为一个外翻肠囊,将每个外翻肠囊置１０ｍｌ培养液中培养１５分钟。旨在比较：体外培养１５分钟后,同一浓度下的Ｇｌｙ－Ｌｙｓ和Ｇｌｙ＋Ｌｙｓ在外翻肠囊各部位的吸收差别,从而确定Ｇｌｙ－Ｌｙｓ在仔猪各肠段的吸收特点。结果表明,同等摩尔浓度下,Ｇｌｙ－Ｌｙｓ组中的赖氨酸和甘氨酸在仔猪空肠中段肠组织的累积量显著大于Ｇｌｙ＋Ｌｙｓ组;从肠囊在１５分钟培养后总的氨基酸摄入量上看,Ｇｌｙ－Ｌｙｓ组的赖氨酸和甘氨酸在空肠中段高于Ｇｌｙ＋Ｌｙｓ组,且二者在赖氨酸上的差异显著。这说明,二肽中甘氨酸和赖氨酸至少在空肠中段的运输系统有别于游离态的甘氨酸和赖氨酸,且对二肽的运输显得比对游离氨基酸的运载更有效。     

Intestinal absorption of end products from digestion of carbohydrates and proteins in the pig

The kinetics of appearance of various nutrients in the portal vein during the postprandial period was studied in conscious pigs by means of a technique based on measurement of the porto-arterial differences in nutrient concentrations simultaneously with that of the portal blood flow rate. The rate and level of appearance of sugars in the portal vein varied with the carbohydrate ingested. It was very rapid after intake of glucose and sucrose, slower after that of maize starch and very slow after that of lactose. The absorption of the latter became very rapid again if it was hydrolysed prior to its ingestion. During absorption, some sugars (fructose or galactose) released from the corresponding sucrose and lactose, respectively during digestion, were partly metabolized into glucose by the enterocyte. The rate of absorption of amino acids released in the digestive tract varied according to the origin of the food ingested, i.e. it was more rapid after intake of wheat or fish proteins than after that of barley. In the case of barley the absorption rate of amino acids differed from that of glucose of the starch. The profile of the amino acid mixtures appearing in the portal vein during absorption differed a little from the profiles of those present in the ingested proteins in the case of essential amino acids and differed much in the case of non essential amino acids. Some essential amino acids (histidine, aromatic amino acids) appeared more rapidly and others more slowly, (lysine, sulphur amino acids, arginine). Because of transaminations, only small amounts of glutamic acid occurred in the portal vein whereas the amounts of alanine as compared to those ingested, were very large. The hierarchy of amino acid absorption was the same whatever the protein studied (fish, wheat, barley). The appearance in the portal vein of alpha-amino nitrogen from enzyme hydrolysates perfused through the duodenum was more rapid than after perfusion of a mixture of free amino acids. During digestion of diets containing 6% cellulose, large amounts of volatile fatty acids (about 2200 mmol/24 h, i.e. 2500 kJ/24h) and lactic acid (60-85 g/24 h) appeared in the portal vein.     

谷氨酰胺对草鱼肠道L-亮氨酸、L-脯氨酸吸收及肠道蛋白质合成的影响

利用肠道离体灌注模型和同位素示踪技术,研究谷氨酰胺对草鱼肠道L-亮氨酸和L-脯氨酸吸收量、肠道组织游离亮氨酸和脯氨酸量、以及对肠道蛋白质合成量的影响。结果表明:谷氨酰胺能够显著增加草鱼肠道对两种氨基酸的吸收量,显著增加肠道组织游离亮氨酸和脯氨酸量,并显著增加肠道蛋白质的合成量;将1.0mmol/L组与5.0mmol/L组谷氨酰胺的试验结果相互比较,无论是肠道吸收总量还是肠道组织游离氨基酸、新蛋白质合成量均没有显著差异;草鱼肠道在吸收亮氨酸和脯氨酸的同时,能够利用吸收的亮氨酸和脯氨酸和肠道蛋白质周转的氨基酸合成新的蛋白质,蛋白质合成量随着亮氨酸和脯氨酸浓度增加呈线性增加关系。本文结果表明,谷氨酰胺能够显著增加草鱼肠道对亮氨酸和脯氨酸的吸收量、能够显著增加肠道蛋白质的合成代谢。     

Influence of fermentable fiber on small intestinal dimensions and transport of glucose and proline in dogs

OBJECTIVE: To determine whether intestinal dimensions and nutrient absorption are influenced by different types of dietary fiber. ANIMALS: 10 adult Beagles of both sexes. PROCEDURE: Dogs were randomly assigned to 2 groups and fed a diet with fermentable fibers (beet pulp and oligofructose) or a nonfermentable fiber (cellulose) for 6 weeks. Effects of the diets on small intestinal dimensions were measured, and transport rates for glucose and proline were determined. Kinetics of glucose and proline uptake were defined in the proximal and middle regions of the small intestine, respectively. RESULTS: Small intestines of dogs fed fermentable fiber had 28% more nominal surface area and 37% more mucosal mass, were 35% heavier, and had 95% higher capacity for carrier-mediated glucose uptake than those of dogs fed a diet with cellulose. Differences were more pronounced in the proximal portion of the intestine. CONCLUSIONS AND CLINICAL RELEVANCE: Diets containing fermentable fibers increase small intestinal dimensions and the capacity for nutrient absorption in dogs. These changes may reduce the risk of enteric infections or aid in treatment of intestinal diseases, particularly those involving reduced nutrient absorption.     

ORIGINAL ARTICLE: Molecular size distribution affects portal absorption rate of casein amino acids in rats

The aim of the study was to determine if differences in the molecular size of two protein sources affect in vivo intestinal absorption rates of amino acids under normal feeding conditions. Accordingly, the portal absorption rate of amino acids was studied in rats fed semi‐synthetic diets containing native casein (NC) or enzymatically hydrolysed casein as the only protein sources. Enzymatic casein hydrolysate (ECH) consisted of a mixture of free amino acids (51.2% with respect to total amino acids) and low molecular weight peptides. Rats were pre‐adapted to the experimental diets for 5 days prior to the absorption studies. Total free amino acid concentrations in portal vein plasma of rats fed ECH diet at 60, 105, 150 and 195 min after feeding were lower (p < 0.05) than those of rats fed NC. Lower (p < 0.05) concentrations of free threonine, proline, tyrosine, valine and tryptophan at all time points, and higher (p < 0.05) leucine at 60 and 105 min were found in rats fed ECH when compared with those fed NC in portal vein plasma. Portal flow rates of threonine, proline, tyrosine and valine were higher in NC at most time points tested, while leucine and lysine were higher for ECH fed rats 60 and 105 min after feeding. In arterial plasma, significantly (p < 0.05) higher concentrations of some individual free amino acids (proline, tyrosine, valine and tryptophan) were determined at 60, 105, 150 and 195 min after feeding, and lower leucine values after 60 and 105 min, in rats fed NC compared with those fed ECH. Results indicate that in normal feeding conditions amino acids from NC and ECH are absorbed at different rates in rats.     

Protein digestibility and absorption of amino acids in various segments of the digestive tract of pigs. 2. Protein and amino acid balances at the end of the small intestine and of the whole digestive tract (apparent and true protein and amino acid digestibility)]

Growing pigs with ileum and ileocecal re-entrant canulae were given 5 different rations (pig fattening feed 1 and 2, rations with dried skim milk, wheat gluten + lysine and wheat + wheat gluten + lysine). The crude protein and amino acid excretion was quantitatively determined with ileum chyme and feces. The calculation of the amino acid balances (apparent and true digestibility) at the end of the small intestine, at the end of the wholedigestive tract and the isolated colon showed characteristic differences for the individual amino acids. On ileum level the amino acids with relatively high endogenous quotas, threonine, tryptophane, alanine, aspartic acid and glycine showed a distinctly lower, the amino acids arginine, methionine, phenylalanine, glutamic acid, proline and tyrosine a distinctly higher digestibilityhan crude protein. In comparison of the values on the feces level, including the true digestibility, these differences are largely balanced out. At the end of the small intestine the absorption of the amino acids is in the main completed. The disappearance rate of amino acids from the colon shows large differences with reference to the different rations as well as the individual amino acids. They were particularly high for various rations as far as proline, tryptophane, glycine and cystine are concerned. If wheat gluten + lysine rations were given, a net synthesis of methionine in the colon could be proved.     

Amino acid profiles in dogs with chronic renal failure fed two diets.

Amino acid profiles and serum albumin and serum total protein concentrations were evaluated in dogs with renal disease. Nine dogs ranging in age from 1 to 15 years were identified as having mild to moderate chronic renal failure (CRF; exogenous creatinine clearance, 0.5 to 2.13 ml/kg of body weight/min). These dogs and a group of 10 clinically normal control dogs were fed a diet containing 31% protein for 8 weeks, at which time serum and urine amino acid assays and clearance studies were performed. All dogs then were fed a diet containing 16% protein for 8 weeks and then reevaluated. Chronic renal failure was associated with mild abnormalities in serum concentrations of amino acids. When fed the higher protein diet, dogs with CRF had lower serum concentrations of glutamine, leucine, proline, and serine and higher serum concentrations of cystathionine and 3-methylhistidine than clinically normal control dogs. When fed the low protein diet, dogs with CRF had lower serum serine concentrations and higher serum concentrations of cystathionine, phenylalanine, and 3-methylhistidine. Urine excretion of amino acids in all dogs on both diets was low, and dogs with CRF had lower renal clearances of 3-methylhistidine than control dogs. There were no significant differences in concentrations of serum albumin and total solids between either group, regardless of diet. We concluded that dogs with mild to moderately severe CRF have mild abnormalities of serum free amino acid concentrations, but renal conservation of essential amino acids is not impaired.     

Intestinal absorption of protein hydrolysis products: a review

Many experimental techniques have allowed researchers to probe the fate of hydrolysis products from proteins in the small intestine. An overview of amino acid and peptide absorption from the small intestine is presented with attention given to historical perspectives that have led to current concepts. Speculation about nutritional significance of these processes is offered. Species differences exist in site of amino acid absorption. Numerous mechanisms are available for the transport of amino acids, including Na(+)-dependent carriers (energy-requiring), Na(+)-independent carriers and diffusion. The relative contribution each transport system makes to absorption is dependent on substrate concentration. Individual amino acids are not absorbed with equal efficiency; methionine usually is absorbed in the greatest proportion. There are interactions among amino acids for transports by specific transport systems. Small peptides (mostly di- and tripeptides) are absorbed from the small intestine more rapidly than are free amino acids; peptides are transported by systems independent of those responsible for transporting free amino acids. Evidence exists that the active transport of these peptides is via a proton gradient. Although the concept that peptides are absorbed intact into the circulation is not universally accepted, evidence supporting the possibility of tissue utilization of these small peptides is accumulating.     

思州鸡肌肉品质分析

随机选取相同条件下放牧饲养的120日龄思州鸡10只,公、母各半,进行肌肉品质测定。结果显示,思州鸡肌肉嫩度好,干物质含量高,钙含量丰富,硒和铁含量较低,锌含量适中;胸肌11种脂肪酸中以油酸、棕榈酸、亚油酸和硬脂酸为主,占脂肪酸总量的92.20%,不饱和脂肪酸含量占69.35%,必需脂肪酸占15.31%;17种氨基酸中以谷氨酸、天冬氨酸、赖氨酸和亮氨酸为主,占氨基酸总量的44.22%,必需氨基酸、鲜味氨基酸、甜味氨基酸、芳香族氨基酸、支链氨基酸和抗氧化氨基酸含量分别为39.40%、26.18%、20.09%、7.06%、18.08%和11.61%。因此,思州鸡肌肉品质优良,肉质风味好。     

深县猪肉质及营养价值分析

本研究选择国外猪种杜洛克和中国地方猪深县猪体重 95 kg 的阉割公猪各 5 头,比较 2 个猪品种背最长肌之间肉质、氨基酸、脂肪酸和微量元素的差异。结果表明:杜洛克猪的肌内水分、肉色、大理石纹、滴水损失、粗蛋白质和脂肪含量低于深县猪(P<0.01);杜洛克猪背最长肌中谷氨酸、天冬氨酸、精氨酸、组氨酸、丝氨酸、脯氨酸、甘氨酸、苏氨酸、半光氨酸、丙氨酸、缬氨酸、苯丙氨酸、异亮氨酸、酪氨酸、亮氨酸、呈味氨基酸总量、必需氨基酸和总氨基酸含量低于深县猪(P<0.01);杜洛克猪背最长肌的饱和脂肪酸含量棕榈酸、豆蔻酸、硬脂酸和花生四烯酸多不饱和脂肪酸亚油酸和亚麻酸低于深县猪(P<0.01);单不饱和脂肪酸棕榈油酸含量低于深县猪(P<0.01),而油酸没有显著性差异;杜洛克猪背最长肌中微量元素钾、锶、铜、锌、硅和铬含量均低于深县猪(P<0.01),镍差异显著(P<0.05)。结果显示,中国地方猪深县猪在肉质及营养价值方面优于瘦肉型的杜洛克猪,为深县猪的品种资源保护和肉产品的开发利用提供依据。     

去盲肠鸡和未去盲肠鸡测定花生粕、胡麻粕、芝麻粕氨基酸消化率的研究

分别用２４只去盲肠和未去盲肠健康公鸡，测定了花生粕、胡麻粕和芝麻粕的氨基酸消化率。结果表明：去盲肠鸡内源氨基酸排泄量显著高于未去盲肠鸡（Ｐ＜０．０５）；在花生粕中，胱氨酸、赖氨酸、天冬氨酸和谷氨酸的ＡＡＤ未去盲肠鸡显著高于去盲肠鸡（Ｐ＜０．０５）；在胡麻粕和芝麻粕中，除酪氨酸和脯氨酸外，其它各种氨基酸及１６种氨基酸总和的ＡＡＡＤ和ＴＡＡＤ未去盲肠鸡显著高于去盲肠鸡（Ｐ＜０．０５）。鸡盲肠微生物对内源及饲料中未消化蛋白质、多肽及氨基酸具有分解作用，干扰饲料ＡＡＡＤ和ＴＡＡＤ测定。对于不易消化、氨基酸含量相对不平衡的低品质蛋白质饲料干扰尤其严重。在测定的３种饼粕中，花生粕氨基酸消化率最高，胡麻粕次之。过度热处理的芝麻粕氨基酸平均消化率为４７．３％，赖氨酸消化率为２１．７％。     

Effect of acute deficiency of dietary proline on proline balance in the rat small intestine and liver

Introduction Proline is widely found in all types of mammalian tissue, and accounts for about 20% of the amino acids that constitute collagen (A dams 1970). Proline is nutritionally nonessential but biologically it is an important amino acid and consequently mammalian organisms synthesize the required amounts of proline even in the absence of sufficient proline consumption via food. The metabolism of higher animals is unique, and amino acid metabolism differs from one tissue to the next. Some organs are capable of synthesizing nonessential amino acids for use throughout the body. For example, arginine is primarily synthesized in the kidney and then released and distributed throughout the body. Pyrroline-5-carboxylate reductase is the enzyme responsible for the final stage of proline synthesis, and its activity has been confirmed in many important organs and tissue such as the cartilage, liver, small intestine, kidney and thymus gland (H erzfeld et al. 1977; S mith and P hang 1978). However, the different levels of pyrroline-5-carboxylate reductase activity among these organs has led to the belief that different amounts of proline are synthesized in these organs. In order to ascertain biological responses to dietary proline deficiency, it is important to identify the organs that release and distribute proline throughout the body when insufficient proline is consumed through the diet, thus reducing the blood proline concentration. Few studies have investigated this issue, but when ascertaining biological responses to dietary proline deficiency, it is more important to elucidate the effect of dietary proline deficiency on the metabolism of proline and other amino acids that are closely related metabolically to proline, in proline synthesizing organs. One of the most effective ways to assess amino acid metabolism in a target tissue of higher animals is to measure the difference between the arterial and venous concentrations of amino acids. I shikawa (1974) measured arteriovenous differences in order to examine the release of proline from the kidney and small intestine of fasted rats and the uptake of proline by the liver. In a previous study, it was found that when the plasma proline concentration was reduced to the fasting level by the consumption of a proline-deficient diet, proline was released from the kidney (W atanabe et al. 1995, 1997). In the present study, to ensure the induction of dietary proline deficiency, a completely purified diet containing all amino acids except for proline was prepared and fed to rats under experimental conditions. To investigate the role of the small intestine and liver in supplying and ingesting proline when the uptake of proline through food is restricted, the release and uptake of amino acids in the small intestine and liver were assessed by measuring carotid artery–portal vein and portal–hepatic vein differences in proline in rats.     

Absorption and use of differently structured protein isolates by rats

Differently structured isolated proteins with the same amino acid composition were tested with growing albino rats in an N-balance and absorption experiment. The following items were tested: --isolated horse bean protein --hydrolysed isolated horse bean protein with an amino acid supplement to make up for losses due to hydrolysis --horse bean protein-casein (1:1) fibres --isolated horse bean protein with an amino acid supplement to achieve the same amino acid concentrations as in the horse bean protein-casein fibres. The lowest digestibility and utilisation values were ascertained for the hydrolysed protein. Endogenous N-excretion calculated according to the isotope dilution method was higher than for intact proteins, the transport of the chyme in the digestive tract and the true absorption of N in the small intestine had significantly diminished. In comparison with horse bean protein supplemented with amino acids, the horse bean protein-casein fibres showed decreased protein utilisation and increased endogenous N-excretion. Independent of the protein fed and of the time after feeding a relatively constant endogenous N-quota of approximately 70% could be ascertained in the chyme in the small intestine. In contrast to this, the relation between exogenous and endogenous N determined from the contents of the large intestine proved to be dependent on the intermediary utilisation of the protein fed.     

Relationship among Plasma Amino Acids, C-Reactive Protein, Illness Severity, and Outcome in Critically Ill Dogs

Background: Alterations in circulating amino acids have been documented in animal models and in critically ill people but have not been evaluated in dogs with spontaneously occurring disease.
Hypothesis/Objectives: To compare amino acid concentrations in critically ill dogs and healthy controls and to investigate potential relationships among amino acids, markers of inflammation, illness severity, and clinical outcome.
Animals: Forty-eight critically ill dogs and 24 healthy control dogs.
Methods: Plasma was analyzed for amino acids and C-reactive protein (CRP) was measured in serum. The Fischer ratio (the molar ratio of branched chain amino acids [BCAA] to aromatic amino acids [AAA]) and survival prediction index (SPI2) were calculated.
Results: Median CRP concentrations were significantly higher in the critically ill dogs compared with controls ( P < .001). Critically ill dogs had significantly lower concentrations of alanine ( P = .001), arginine ( P < .001), citrulline ( P < .001), glycine ( P < .001), methionine ( P < .001), proline ( P < .001), and serine ( P = .001) but significantly higher concentrations of lysine ( P = .02) and phenylalanine ( P < .001; Table 1 ). This pattern resulted in a significantly lower Fischer ratio ( P = .001) in the critically ill group. Median SPI2 score was significantly higher in dogs that survived ( P = .03). Concentrations of arginine ( P = .02), isoleucine ( P = .01), leucine ( P = .04), serine ( P = .04), valine ( P = .04), total BCAA ( P = .03), and the Fischer ratio ( P = .03) were significantly higher in survivors compared with nonsurvivors.  

  Table 1.   Comparison between critically ill and healthy control dogs and among different subgroups of diseases within the critically ill group.     

16.

亮氨酸和缬氨酸在绵羊骨骼肌和肾组织中的分解代谢     

董国忠 《畜牧兽医学报》1992,23(2):102-106

本研究测得5头15月龄体重33.5±2.5千克的美利奴羯羊血浆、骨骼肌和肾组织中游离分支氨基酸含量为:缬氨酸含量>亮氨酸含量)异亮氨酸含量。组织中游离分支氨基酸含量略高于血浆中含量。不同组织(骨骼肌和肾)中分支氨基酸转氨酶(EC 2.6.1.42)在作用底物(亮氨酸或缬氨酸)相同时的Km值相近似,但Vmax却呈现较大的差异。组织中游离亮氨酸和缬氨酸在不同含量水平下的转氨基分解量显著不同(P<0.01)。当组织中游离亮氨酸和缬氨酸含量在1.5～5倍于正常组织水平范围内变化时,分解量的增加幅度为0.5～3倍。实验结果初步表明,酶的活性诱导作用是绵羊组织中分支氨基酸代谢性拮抗作用机制之一。     

17.

红肉火龙果不同品种的果实品质和氨基酸组成比较     

邓英毅  何嘉楠 《中国果业信息》2020,49(2)

摘 要:为了综合评价广西主栽的不同红肉火龙果品种的果实品质特性和氨基酸组成,以金都1号、大红、蜜宝、美龙3号四个品种为研究对象,对其果实品质和氨基酸组分及含量等指标进行全面系统的比较,旨在为火龙果的种植生产、加工和食用等提供理论依据。结果表明：4个火龙果品种果实外形端正,色泽鲜艳,品质佳,其中金都1号果实最大,美龙3号最小;金都1号和蜜宝的果形为近圆形,大红和美龙3号为椭圆形;萼片都是三角形,金都1号和大红较长,蜜宝较短;萼片数最多的是大红,最少的是蜜宝;果皮最厚的是美龙3号,最薄的是蜜宝;可食率最高的是蜜宝;金都1号果实的可溶性固形物、可溶性糖、还原糖、可滴定酸、维生素C、甜味氨基酸、苏氨酸、蛋氨酸和脯氨酸的含量以及必需氨基酸在总氨基酸中的比例最高,大红的17种氨基酸总量、必需氨基酸、半必需氨基酸、鲜味氨基酸、芳香族氨基酸、赖氨酸、苯丙氨酸、缬氨酸、亮氨酸、异亮氨酸、组氨酸、精氨酸、门冬氨酸和甘氨酸的含量最高,蜜宝的胱氨酸、丙氨酸、丝氨酸和谷氨酸的含量最高,美龙3号的酪氨酸含量最高。4个红肉火龙果品种果实所含的17种氨基酸中,排在前五位的是谷氨酸、脯氨酸、精氨酸、亮氨酸、门冬氨酸。综合进行评价,金都1号的综合品质性状最佳,其次是大红。     

18.

Quantitative measurement of endogenous amino acid absorption in unanaesthetized pigs   总被引：1，自引：0，他引：1  

A Rerat  P Vaissade  P Vaugelade 《Archives of Animal Nutrition》1988,38(6):463-479

The present experiment was carried out with 11 pigs (mean body weight: 53.9 +/- 1.3 kg) fitted with permanent catheters in the portal vein and carotid artery and with an electromagnetic flow probe around the portal vein. They were each subjected to 2 or 3 trials at 3 to 4-day intervals. During each trial the animals received after a previous fasting of 20 h a given amount of a protein-free diet (200 to 1200 g). The blood was collected either continuously for a quantitative determination of amino nitrogen, reducing sugars, urea and ammonia (number of meals 12, mean intake: 727 +/- 60 g) or discontinuously every 30 min between 0 and 8 h after the meal for amino acid analysis (number of meals 8; mean intake 709 +/- 105 g). A rather constant appearance (2 g/h) of amino acids in the portal blood was observed throughout the postprandial period. The intestinal absorption of each amino acid was however variable and represented between 10 and 50% of the daily requirements of the animal during the measuring period (8 h). Glutamine and to a less extent glutamic acid were exceptions as they were taken up by the gut wall from the arterial blood. There was also a marked synthesis of ornithine and citrulline by the latter. Because of the low blood level of urea, there were no apparent exchanges of urea between the blood and the intestine; in contrast, the ammonia absorption represented about 70% of that observed after ingestion of normal protein diets. Most amino acids are largely taken up by the liver and peripheral tissues, but in the case of alanine the syntheses exceed the uptake.     

19.

Cloning of canine Toll-like receptor 7 gene and its expression in dog tissues   总被引：1，自引：0，他引：1  

Okui Y  Kano R  Maruyama H  Hasegawa A 《Veterinary immunology and immunopathology》2008,121(1-2):156-160

Toll-like receptor 7 (TLR7) is activated by single strand RNA and imidazoquinoline compounds, and induces interferon production. In this study, canine TLR7 cDNA was cloned and sequenced. The full-length cDNA of canine TLR7 gene was 3419bp, encoding 1032 amino acids. The similarities of canine TLR7 with human and mouse TLR7 were 84 and 80% at the nucleotide sequence level, and 86 and 79% at amino acid sequence level, respectively. Further, the expression of TLR7 mRNA was investigated in canine normal tissues by semiquantitative RT-PCR analysis. The common expression level of TLR7 mRNA in tissues from three dogs examined was in large intestine, lung, pancreas, small intestine and skin, though the expression level in each tissue was varied among these healthy dogs. In other tissues (kidney, liver, lymph node, spleen, adrenal gland, and PBMCs), the level of TLR7 mRNA expression was different in individuals.     

20.

南板蓝根氨基酸的分析   总被引：5，自引：0，他引：5  

廖富华 《中国兽药杂志》2003,37(3):39-41

利用氨基酸分析仪对南板蓝根氨基酸进行分离测定，证实其含有脯氨酸、甘氨酸、苏氨酸、蛋氨酸、丙氨酸、天门冬氨酸、谷氨酸、半胱氨酸、苯丙氨酸、酪氨酸、缬氨酸、异亮氨酸、亮氨酸、丝氨酸等十四种氨基酸，但未发现精氨酸、赖氨酸和组氨酸。     

亮氨酸和缬氨酸在绵羊骨骼肌和肾组织中的分解代谢

本研究测得5头15月龄体重33.5±2.5千克的美利奴羯羊血浆、骨骼肌和肾组织中游离分支氨基酸含量为:缬氨酸含量>亮氨酸含量)异亮氨酸含量。组织中游离分支氨基酸含量略高于血浆中含量。不同组织(骨骼肌和肾)中分支氨基酸转氨酶(EC 2.6.1.42)在作用底物(亮氨酸或缬氨酸)相同时的Km值相近似,但Vmax却呈现较大的差异。组织中游离亮氨酸和缬氨酸在不同含量水平下的转氨基分解量显著不同(P<0.01)。当组织中游离亮氨酸和缬氨酸含量在1.5～5倍于正常组织水平范围内变化时,分解量的增加幅度为0.5～3倍。实验结果初步表明,酶的活性诱导作用是绵羊组织中分支氨基酸代谢性拮抗作用机制之一。     

红肉火龙果不同品种的果实品质和氨基酸组成比较

摘 要:为了综合评价广西主栽的不同红肉火龙果品种的果实品质特性和氨基酸组成,以金都1号、大红、蜜宝、美龙3号四个品种为研究对象,对其果实品质和氨基酸组分及含量等指标进行全面系统的比较,旨在为火龙果的种植生产、加工和食用等提供理论依据。结果表明：4个火龙果品种果实外形端正,色泽鲜艳,品质佳,其中金都1号果实最大,美龙3号最小;金都1号和蜜宝的果形为近圆形,大红和美龙3号为椭圆形;萼片都是三角形,金都1号和大红较长,蜜宝较短;萼片数最多的是大红,最少的是蜜宝;果皮最厚的是美龙3号,最薄的是蜜宝;可食率最高的是蜜宝;金都1号果实的可溶性固形物、可溶性糖、还原糖、可滴定酸、维生素C、甜味氨基酸、苏氨酸、蛋氨酸和脯氨酸的含量以及必需氨基酸在总氨基酸中的比例最高,大红的17种氨基酸总量、必需氨基酸、半必需氨基酸、鲜味氨基酸、芳香族氨基酸、赖氨酸、苯丙氨酸、缬氨酸、亮氨酸、异亮氨酸、组氨酸、精氨酸、门冬氨酸和甘氨酸的含量最高,蜜宝的胱氨酸、丙氨酸、丝氨酸和谷氨酸的含量最高,美龙3号的酪氨酸含量最高。4个红肉火龙果品种果实所含的17种氨基酸中,排在前五位的是谷氨酸、脯氨酸、精氨酸、亮氨酸、门冬氨酸。综合进行评价,金都1号的综合品质性状最佳,其次是大红。     

Quantitative measurement of endogenous amino acid absorption in unanaesthetized pigs

The present experiment was carried out with 11 pigs (mean body weight: 53.9 +/- 1.3 kg) fitted with permanent catheters in the portal vein and carotid artery and with an electromagnetic flow probe around the portal vein. They were each subjected to 2 or 3 trials at 3 to 4-day intervals. During each trial the animals received after a previous fasting of 20 h a given amount of a protein-free diet (200 to 1200 g). The blood was collected either continuously for a quantitative determination of amino nitrogen, reducing sugars, urea and ammonia (number of meals 12, mean intake: 727 +/- 60 g) or discontinuously every 30 min between 0 and 8 h after the meal for amino acid analysis (number of meals 8; mean intake 709 +/- 105 g). A rather constant appearance (2 g/h) of amino acids in the portal blood was observed throughout the postprandial period. The intestinal absorption of each amino acid was however variable and represented between 10 and 50% of the daily requirements of the animal during the measuring period (8 h). Glutamine and to a less extent glutamic acid were exceptions as they were taken up by the gut wall from the arterial blood. There was also a marked synthesis of ornithine and citrulline by the latter. Because of the low blood level of urea, there were no apparent exchanges of urea between the blood and the intestine; in contrast, the ammonia absorption represented about 70% of that observed after ingestion of normal protein diets. Most amino acids are largely taken up by the liver and peripheral tissues, but in the case of alanine the syntheses exceed the uptake.     

Cloning of canine Toll-like receptor 7 gene and its expression in dog tissues

Toll-like receptor 7 (TLR7) is activated by single strand RNA and imidazoquinoline compounds, and induces interferon production. In this study, canine TLR7 cDNA was cloned and sequenced. The full-length cDNA of canine TLR7 gene was 3419bp, encoding 1032 amino acids. The similarities of canine TLR7 with human and mouse TLR7 were 84 and 80% at the nucleotide sequence level, and 86 and 79% at amino acid sequence level, respectively. Further, the expression of TLR7 mRNA was investigated in canine normal tissues by semiquantitative RT-PCR analysis. The common expression level of TLR7 mRNA in tissues from three dogs examined was in large intestine, lung, pancreas, small intestine and skin, though the expression level in each tissue was varied among these healthy dogs. In other tissues (kidney, liver, lymph node, spleen, adrenal gland, and PBMCs), the level of TLR7 mRNA expression was different in individuals.     

南板蓝根氨基酸的分析

利用氨基酸分析仪对南板蓝根氨基酸进行分离测定，证实其含有脯氨酸、甘氨酸、苏氨酸、蛋氨酸、丙氨酸、天门冬氨酸、谷氨酸、半胱氨酸、苯丙氨酸、酪氨酸、缬氨酸、异亮氨酸、亮氨酸、丝氨酸等十四种氨基酸，但未发现精氨酸、赖氨酸和组氨酸。