Amino acid production in the isolated and perfused rumen wall of sheep

The metabolism of amino acids and urea in an isolated perfused wall of sheep rumen was studied by the method of organ perfusion, using 3 kinds of perfusate. In experiments with semisynthetic perfusate containing urea (SPurea) the levels of lysine, valine, glutamic acid and alanine increased at a simultaneous decrease of levels of leucine, arginine, aspartic acid, threonine and methionine. In perfusions with the semisynthetic medium without urea (SP) the levels of lysine, valine, phenylalanine, isoleucine, glutamic acid, glycine and alanine increased, the level of threonine dropped. In perfusions with whole autologous blood (KP) the levels of valine, glutamic acid and alanine increased, the level of arginine decreased. The level of urea decreased sharply at using SPurea and KP, however, the equal cumulation of ammonia (200-400 mumol x 1(-1)) was found in all three types of perfusate after 2-hr perfusion. Moreover, in experiments with SP a low level of urea was found already after 5-min. of perfusion. The results of the experiments suggest that the rumen wall is capable of producing amino acids also without the contents of rumen, and that independently on the presence or absence of urea as a nitrogen source.     

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。     

In vitro transport of amino acids across the rumen mucosa in sheep]

Transfer of six amino acids through rumen epithelium of sheep has been studied on mucous and serous sides. Amino acids were classified into two groups: 1. lysine-arginine-glutamic acid, 2. glycine-alanine-leucine. The transfer of amino acids in triads was measured after 60 min. incubation. To determine amino acids transfer through rumen epithelium, three concentrations of amino acids were used: 1500: 150 and 15 mumol per 50 ml. In the first group of amino acids, the highest transfer of arginine was found in comparison with lysine and glutamic acid in all concentrations. The lowest transfer was found in glutamic acid. It follows from this that initial concentration of amino acids in the first group had no effect on amino acids transfer as far as the transfer of amino acids was as follows in all concentrations: arginine greater than lysine greater than glutamic acid. On the other hand, the composition of amino acids and initial concentration of amino acids in the second group exhibited the marked dependence on the transport of amino acids. The transfer of amino acids at the concentration of 1500 mumol per 50 ml was as follows: the passage of amino acids was the highest while this was lowest in alanine and leucine, at the concentration 150 mumol per 50 ml the highest transfer was found in alanine, it was lower in glycine and lowest in leucine and at the concentration 15 mumol per 50 ml the transfer of glycine was highest, lower in leucine and lowest in alanine.(ABSTRACT TRUNCATED AT 250 WORDS)     

大肠杆菌新菌毛抗原的研究Ⅱ．菌毛抗原蛋白质特性测定

用保温法和裂解法可以有效提取Ｆ_(１９８７)新菌毛抗原蛋白质；该菌毛蛋白经区带电泳显示主、次两个组分，在０．０６ｍｏｌ／ＬｐＨ８．６巴比妥缓冲液电泳条件下，均向阳极泳动；免疫电泳显示两条沉淀线；其分子量为１９１００Ｄａ；等电点为３．０；由天门冬氨酸、苏氨酸、丝氨酸、谷氨酸、甘氨酸、丙氨酸、缬氨酸、异亮氨酸、亮氨酸、酪氨酸、苯丙氨酸、赖氨酸、组氨酸、精氨酸、脯氨酸、胱氨酸等１６种氨基酸组成。     

Some effects of protein deficiency in young growing pigs. II. Blood plasma free amino acids

The influence of protein deficiency, rehabilitation and total starvation on the free amino acid levels in the blood plasma of pigs has been investigated. It was found that the concentration of most amino acids was reduced during protein deficiency. The levels of leucine, isoleucine and valine were diminished by the greatest proportion, followed by threonine, tyrosine and citrulline. During the first few weeks of protein deficiency the levels of lysine, histidine and arginine were slightly increased, but later decreased below control values. Concentrations of glycine and alanine were altered in a similar way except that the initial increase was much more pronounced. The concentrations of most of these amino acids returned to control levels after rehabilitation. Total starvation led to an increase in concentration of leucine, isoleucine, valine, threonine and to a smaller extent phenylalanine, lysine, citrulline and arginine. The concentration of glycine, alanine and glutamic acid were very much reduced. The level of urea in the circulation dropped reversibly during protein deficiency and increased very much during total starvation.     

Quantitative estimation of amino acids in cysticercus of taenia hydatigena

Cyst membranes of Cysticercus tenuicollis, the larval stage of Taenia hydatigena, contained 14 amino acids, namely lysine, histidine, arginne, aspartic acid, threonine, serine, glutamic acid, proline, glycine, alanine, isoleucine and leucine. Methionine was present in traces. In comparison, the cyst fluid was deficient in histidine, arginne, threonine, methionine and valine and the scolices did not have threonine, serine, glutamic acid and methionine. The membrane contained large quantities of amino acids in comparison to the other components of the cyst.     

柑橘提取物对肥育猪后肠食糜蛋白质代谢产物的影响

【目的】通过研究柑橘提取物对肥育猪后肠食糜蛋白质代谢产物的影响,旨在为柑橘提取物从源头调控臭气的产生提供依据。【方法】选取108头56日龄(19.73±0.39)kg杜×长×大猪,公母各半,随机分为3组,每组分6栏,每栏6头猪。对照组饲喂基础饲粮,抗生素组在基础饲粮中添加75 g/t金霉素,柑橘提取物组在基础饲粮中添加柑橘提取物(56～112日龄添加250 mL/t柑橘提取物,113～194日龄添加200 mL/t柑橘提取物)。194日龄时收集肥育猪盲肠和结肠食糜,测定食糜中游离氨基酸、酚和吲哚类物质、生物胺的含量。【结果】(1)在盲肠食糜中,与对照组相比,柑橘提取物组和抗生素组牛磺酸、天冬氨酸、丙氨酸、缬氨酸、亮氨酸、赖氨酸、组氨酸、精氨酸、吲哚和甲胺含量均显著降低(P<0.05)。与对照组相比,柑橘提取物有降低苏氨酸、丝氨酸、谷氨酸、甘氨酸、瓜氨酸、异亮氨酸、脯氨酸和粪臭素含量的趋势(0.05≤P<0.10),苯酚、腐胺、酪胺和精胺含量均显著降低(P<0.05)。与抗生素组相比,柑橘提取物组腐胺和酪胺含量均显著减少(P<0.05)。(2)在结肠食糜中,与对照...     

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。     

Concentration of free amino acids in the blood plasma of sheep with different amounts of nitrogen in the feed

Trials were conducted with four adult sheep of the Merino breed, live weight 45 to 50 kg, fed two diets with different nitrogen levels (7.6 g nitrogen per day as protein or 24 g nitrogen per day with an addition of 17.4 g urea nitrogen to 7.6 g nitrogen as protein). The following findings were obtained: the concentration of free amino acids in blood plasma in the 9th, 12th, 15th, 18th and 22nd weeks from the beginning of feeding with both diets was lower, in most of the analyzed amino acids, three hours after feeding than before feeding. The results show that at an increased intake of urea nitrogen the concentration increases of the free amino acids lysine, serine, glutamic acid, glycine, valine and isoleucine before feeding. Three hours after feeding these differences are less pronounced. An increase is only recorded in the concentration of arginine, glutamic acid and glycine, whereas the concentration of alanine decreases.     

Resting concentrations of the plasma free amino acids in horses following chronic submaximal exercise training

Six horses were conditioned on a treadmill at a constant speed of 5.6 km/hr on a 12.5% grade for gradually increasing periods of time over 14 days in order to determine the effect of repeated submaximal exercise on the concentrations of plasma free amino acids, protein metabolism, and plasma volume. Following 14-days of training, plasma volume increased (29%, P<0.05), as did total circulating content of plasma protein, albumin and urea. Urinary urea nitrogen excretion decreased (P<0.05) with exercise training. After the first week of training, the concentration of glycine had decreased (P<0.05) and the concentrations glutamic acid, arginine and alanine were increased (P<0.05) when compared to their corresponding pre-training (control week) levels. Compared to pretraining levels, there were decreases (P<0.05) in aspartic acid, histidine, arginine, valine, phenylalanine, isoleucine, and lysine, following the second week of training. Following a week of recovery, all resting concentrations of plasma free amino acids; when compared to their pretraining control; had decreased, with the exception of three nonessential amino acids (glutamic acid,serine, and glycine). Based upon the results of the present study, it would appear that exercise training produced a significant change in the amino acid and protein metabolism of the horse.     

Changes in amino acid levels in bacteria adhering to rumen epithelium in sheep after oral administration of very low doses of mercury

The effect of low concentrations of mercury taken in the diet (4 mg per a head and day) on the amino acid composition in the proteins of rumen bacteria adhering to the dorsal and ventral parts of the rumen was studied in six sheep. Though the mercury did not influence the amino acid concentration in hydrolyzates of epimural bacteria, low-mercury doses caused significant changes of some amino acids, as compared with the control group of animals. The levels of alanine, histidine, threonine, serine and glycine were significantly decreased and at the same time the levels of proline, valine, isoleucine, tyrosine, lysine and phenylalanine were significantly increased. It was stated in our experiment that the levels of histidine, alanine and threonine in hydrolyzates of epimural bacteria of the rumen were significantly decreased both in the sheep given the balanced feed ration with additions of mercury and nitrogen (according to the standard) and in the sheep given a low-nitrogen diet. Similarly, the levels of proline, tyrosine and phenylalanine in the hydrolizates of epimural bacteria in rumen were significantly increased both with the low-nitrogen diet and in the normal -nitrogen diet with mercury supplement. The results suggest that unexplained disorders frequently occurring in the microbial synthesis in the rumen might be caused by long-continued administration of feed contaminated with extremely low concentrations of heavy metals. The problem deserves detailed investigation in future studies, oriented to explaining the biosynthesis disorders in rumen, reducing the production ability of ruminants.     

Absorption of amino acids from the perfused ovine rumen]

The experiments with extracoroporeal perfusion of sheep rumen were performed [Leng et al., 1977]. Bovine plasma, diluted in a 1:1ratio with an isotonic solution of sodium chloride, was used for four perfusions, and autologous blood was used for two perfusions in the course of 150 minutes. After 60 minutes perfusion 20 g enzymatic casein hydrolyzate were applied to the rumen. The levels of free amino acids in the perfusate were recorded after 60 minutes' perfusion [the first phase of perfusion] and at the end of the experiment [the second phase]. The levels of lysine, aspartic acid and glutamic acid increased after perfusions with bovine plasma during the first phase, the levels of glutamic acid, phenylalanine, and in one case of alanine, increased after perfusions with autologus blood. Simultaneously the level of valine decreased after perfusions with bovine plasma, and after perfusions with blood the levels of arginine and valine, and/or lysine, dropped. During the second phase of perfusion, the levels of all the observed amino acids except methionine [bovine plasma], and/or orginine and methionine [blood] rose in the perfusate. The experiments showed that the level of amino acids in the rumen content presented a decisive factor affecting amino acid absorption from the rumen into the blood. Transformation of the amino acids during their passage through the remen wall may be assumed, and glutamic acid is one of the chief products of this process.     

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.     

蓟马取食对苜蓿氨基酸组成及含量的影响

为了探究蓟马取食对苜蓿(Medicago sativa L.)氨基酸组成及含量的影响,本研究以'草原2号'(Medicago varia Martin.'Caoyuan No.2')感蓟马品种和'草原4号'(Medicago sativa L.'Caoyuan No.4')抗蓟马品种为材料,分别进行牛角花齿蓟马(Odo...     

Individual variation in the content of free amino acids observed in the blood and muscle of chicks fed a single meal daily

1. Fifty broiler chicks in individual cages, were fed on a balanced diet ad libitum until 10 d old and then given a single meal daily. Blood and pectoral muscle samples were taken from each. Free aspartic acid, threonine, serine, glutamic acid, glycine, alanine, valine, cystine, isoleucine, leucine, phenylalanine, lysine and arginine were determined.

2. Free amino acid concentrations varied greatly between birds. Values for the coefficient of variation ranged from 0.21 for serine in both tissues to 0.571 and 0.749 for valine and lysine in blood and muscle respectively.

3. Many correlations for pairs of amino acids did not seem related to the body weight of chicks.     

Individual differences and repeatability of post-prandial changes of plasma-free amino acids in young horses

Few data are available on post-prandial changes of plasma amino acids (AAs) in horses and on the repeatability and the individual variance on different sampling days. The objective of the present study was to measure pre- and post-prandial concentrations of plasma AA in 10 yearling horses. Blood samples were taken on days 1 and 40 of the study before feeding of hay, oats and soya meal and over an 8 h post-prandial period in 2-h intervals. The plasma AAs were measured by high-pressure liquid chromatography after ortho-phthalaldehyde derivatization. Mean fasting concentrations of the AAs were not significantly influenced by the individuum and sampling day. Repeatability of the fasting AA levels in the individual horses on two different sampling days was only found for histidine, 3-methylhistidine, methionine, tryptophan and taurine. While the absolute post-prandial AA concentrations differed between sampling days, the relative changes were comparable. All AA concentrations except 3-methylhistidine increased after feeding by 13% to more than 200% of their fasting values if the combined data of both days were analysed. Four hours after feeding the concentrations of arginine, asparagine, lysine, leucine, isoleucine and threonine, decreased more than 20%. Histidine, methionine, phenylalanine, valine, tryptophan, glutamine, glycine, tyrosine and taurine concentrations decreased by less than 20%. Concentrations of aspartic acid, glutamic acid, ornithine, serine and citrulline remained elevated. Most AA approached the fasting concentrations at 8 h, only glycine increased between 6 and 8 h after meal and 3-methyl-histidine concentrations were constant throughout the entire period. In conclusion, the pre-prandial plasma AA in horses appeared less influenced by individuum or sampling day than post-prandial plasma AA concentrations. Therefore, plasma AA concentrations should be interpreted only under well-defined conditions, especially regarding the feeding regimen.     

Level of free amino acids in the milk of cows in relation to values in arterial and venous blood

The levels of free amino acids in cow's milk vary greatly. The highest value of 164.484 mumol/l was recorded in glutamic acid, followed by glycine, alanine, lysine, and the lowest values were found in cystine, methionine, phenylalanine, tyrosine and isoleucine (5--10 mumol/l). The levels of free amino acids in milk and their order differ from the values and the order in blood. For a large proportion of free amino acids, significant to highly significant relations exist between the levels in arterial blood and venous blood before and after milking. On the other hand, significant positive correlations were found only between the level of cystine in arterial blood and in venous blood after milking, between threonine level in arterial blood and in venous blood before milking, and a highly significant negative correlation was recorded between the leucine level in venous blood before milking and the respective value in milk.     

青贮饲用油菜对湖羊生长性能、屠宰性能、瘤胃发酵及器官发育的影响

本试验旨在探究青贮饲用油菜对湖羊生长性能、屠宰性能、瘤胃发酵及器官发育的影响。选取出生日期、胎次和体重相近的健康断奶湖羊公羔12只,随机分为2组,每组6只羊。2组分别饲喂花生秧全混合日粮(花生秧组)和青贮饲用油菜全混合日粮(油菜组)。试验期60 d。结果表明:与花生秧组相比,油菜组湖羊体重(P=0.043)和平均日增重(P=0.011)显著提高;胴体重有提高的趋势(P=0.062);瘤胃(P=0.028)、皱胃(P=0.029)、空肠(P=0.008)以及小肠(P=0.013)的重量显著提高,十二指肠重量有提高的趋势(P=0.055);瘤胃占宰前活重比例显著提高(P=0.033),十二指肠(P=0.048)和盲肠(P=0.016)占宰前活重比例显著降低;背最长肌粗蛋白质含量有提高的趋势(P=0.062),苏氨酸(P=0.019)、脯氨酸(P=0.010)、甘氨酸(P=0.008)、丙氨酸(P=0.016)、缬氨酸(P=0.039)、蛋氨酸(P=0.007)、异亮氨酸(P=0.023)、亮氨酸(P=0.017)、酪氨酸(P=0.025)、苯丙氨酸(P=0.012)、赖氨酸(P=0.033)、精氨酸(P=0.024)、总氨基酸(P=0.028)、必需氨基酸(P=0.021)、非必需氨基酸(P=0.036)含量显著增加,丝氨酸(P=0.056)、谷氨酸(P=0.052)和组氨酸(P=0.055)含量有增加的趋势;瘤胃液中乙酸(P=0.062)和总挥发性脂肪酸(P=0.087)含量有提高的趋势。由此可见,青贮饲用油菜同比例替代花生秧提高了湖羊生长性能、瘤胃发酵速率和胃肠道发育,同时具有提高肌肉中蛋白质含量的潜力,改善了肌肉的风味和营养价值,提高了肉品质。     

Effects of exogenous amino acids on the multiplication of porcine Escherichia coli

The multiplication rates of 70 porcine Escherichia coli strains were compared in minimal medium and in medium supplemented with aspartic acid, lysine, serine and threonine, which were the amino acids taken up during multiplication of porcine E. coli in a complex medium. The effects of these amino acids singly or in combinations and the amino acids norleucine and norvaline on the growth of porcine E. coli were studied. Together, aspartic acid, threonine, serine and lysine increased the multiplication rates of 42.9% of the strains, an effect traced to aspartic acid, but they had no effect on an equal number of strains. The rest were inhibited, and this effect was traced to serine. Cysteine, threonine, leucine and phenylalanine singly inhibited some or all of the strains tested. Norleucine and to a lesser extent, norvaline greatly prolonged the lag phase of culture in minimal medium. The inhibitory effect of norleucine was reversed by only methionine, although isoleucine, leucine and valine which were more effective in norvaline inhibition, also showed limited antagonism to norleucine inhibition.     

Amino acid concentrations in blood serum of horses performing long lasting low-intensity exercise

The aim of this work was to evaluate the changes in the concentrations, after two rides different for distance covered, of different amino acids in endurance horses. Blood samples have been collected from horses just before the start, at the top of a steep slope (819 m difference in height) and just at the end of a 32-km endurance ride. A second group, competing in a 72 km endurance ride, has also been sampled immediately before and after the race. In serum samples, the concentrations of alanine, arginine, asparagine, glycine, isoleucine, histidine, leucine, lysine, methionine, ornithine, phenylalanine, tryptophan, tyrosine and valine have been measured by high-performance liquid chromatography (HPLC). anova and t-test have been used to study the differences in the concentrations of the amino acids. The pre-ride concentrations of the free amino acids were different between the two races, except for methionine and leucine. Differences between start and end race have been found for both groups for all the considered parameters except asparagine, isoleucine, leucine and lysine for the 72 km ride. Increases have been recorded for the shorter and decreases for the longer ride in the blood serum concentrations. Significant increases have also been found between the starting sampling and the second, at the top of the slope, only for alanine, arginine, asparagines, phenylalanine and lysine. The ride length has a significant impact on blood serum amino acids mobilization and uptake; in the shorter race the increases stand only for mobilization, whereas in the longer the decrease can be considered the effect of the onset of the amino acids catabolism.