scholarly journals The rejection of a diet which has been associated with a single administration of an histidine -free amino acid mixture

1974 ◽  
Vol 31 (3) ◽  
pp. 285-296 ◽  
Author(s):  
P. C. Simson ◽  
D. A. Booth
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Consumption ◽  
Preference Test ◽  
Essential Amino Acids ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Two Samples ◽  
Control Load ◽  
Protein Free Diet

1. A protein-free diet, to which an odour had been added, was offered to rats immediately after giving a gastric load of an histidine-free, but otherwise balanced, amino acid mixture. The same diet with a different odour was offered to the rats on another day, after administration of a control load of saline or a balanced amino acid mixture. After access to stock diet for 6 h of 1 d, the rats were offered two samples of protein-free diet, each with one of the two odours.2. The rate of consumption of odorized protein-free diet was depressed 2–4 h after administration of the histidine-free load. In the later preference test, the dietary sample with odour which had been offered after the deficient load was rejected in favour of the sample with the odour which had been offered after the control load.3. Rejection of the deficiency-paired odour in the final preference test did not occur when the histidine-free load had been given 2 h before the rats were first offered odorized diet. Also, there was in these instances no depression of rate of food consumption 2–4 h after loading. This indicated that aversive reactions to the odour were established by association of the odour with some effect of the histidine-free load which had occurred within 2 h of its administration, and that the early depression of intake and the much later rejection during choice were both expressions of these acquired reactions.4. This rapid conditioning of selective rejection did not depend on previous prolonged protein deprivation or on the use of immature rats but did depend upon an intermittent supply of amino acids during 3 d before conditioning. Subcutaneous injection of deficient amino acid mixture did not establish rejection, suggesting that conditioning depended on rapid delivery of the deficient mixture into the circulation.5. It is concluded that the critical biochemical events which lead to the rejection of diets that are imbalanced or deficient in essential amino acids occur soon after ingestion of the diet, and may have been effective in producing a conditioned aversion before any suppression of food intake appears. It is suggested that the depression of food consumption, which is the normal response to an imbalanced diet, is in this instance the result of conditioned response to sensory qualities of the diet rather than to the direct effect of biochemical stimuli.

Effects on wool growth of the infusion of mixtures of amino acids into the abomasum of sheep

1978 ◽  
Vol 90 (1) ◽  
pp. 173-183 ◽  
Author(s):  
P. J. Reis ◽  
D. A. Tunks
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Amino Acid ◽  
Volume Growth ◽  
Fibre Diameter ◽  
Essential Amino Acids ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Standard Mixture ◽  
Wool Growth

SUMMARYMerino sheep were given abomasal infusions of either mixtures of amino acids or protein during periods of 8 or 12 days. Effects on wool growth were measured using autoradiography and a clipping procedure which allowed time for the emergence of the wool fibres. Estimates of volume growth rate, from the autoradiographic measurements, and of mass of wool grown, from clipping, were in good agreement.An infusion of a standard mixture of 13 amino acids, which included ten essential amino acids in approximately the proportions in casein, consistently stimulated wool growth. The mean increases in volume and mass of wool grown, during 30 infusions, were 66 and 67% respectively. A mixture of ten essential amino acids alone appeared to be as effective as the standard mixture for stimulating wool growth, and there were no significant differences between the effects on wool growth of casein and the standard mixture of amino acids.The omission of methionine from an infusion of the standard mixture of amino acids, or from a mixture of essential amino acids only, inhibited wool growth rate; both fibre diameter and length of wool grown per day were reduced to below the control values. In addition, the strength of the fibres was considerably reduced.Infusions of zein and of an amino acid mixture simulating the essential amino acid composition of zein both inhibited wool growth rate, due to a reduction in fibre diameter. Similar effects on wool growth were observed when any one of three essential amino acids (lysine, isoleucine or leucine) was omitted from an infusion of the standard mixture of amino acids. The omission of five other essential amino acids (arginine, histidine, phenylalanine, threonine or valine) from the infusion, or variations in the proportions of leucine, lysine or methionine, had no appreciable effects on wool growth.

scholarly journals Effect of leucine on intestinal absorption of tryptophan in rats

1985 ◽  
Vol 54 (3) ◽  
pp. 695-703 ◽  
Author(s):  
Chisae Umezawa ◽  
Yuko Maeda ◽  
Kanji Haba ◽  
Mariko Shin ◽  
Keiji Sano
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Intestinal Absorption ◽  
Digestive Tract ◽  
Causal Relation ◽  
Control Diet ◽  
Essential Amino Acids ◽  
Amino Acid Mixture ◽  
Side Chain ◽  
Acid Mixture

1. To elucidate the causal relation between leucine and the lowering of hepatic NAD content of rats fed on a leucine-excessive diet (Yamada et al. 1979), the effect of leucine on intestinal absorption of tryptophan was investigated.2. Co-administration of [3H]tryptophan and leucine, with leucine at ten times the level of tryptophan, delayed absorption of L-[side chain 2,3-3H]tryptophan from the digestive tract and incorporation of [3H]tryptophan into portal blood, the liver and a protein fraction of the liver. After 120 min, more than 95% of tryptophan was absorbed whether [3H]tryptophan was administered with or without leucine.3. Co-administration of a mixture of ten essential amino acids, in proportions simulating casein, with [3H]tryptophan markedly delayed absorption of tryptophan from the digestive tract. The addition of supplementary leucine to the amino acid mixture, however, caused no further delay.4. In rats prefed a leucine-excessive diet for 1 week [3H]tryptophan was absorbed at the same rate as in rats fed on a control diet.5. The results indicate that competition between tryptophan and leucine for intestinal absorption did not cause lowering of hepatic NAD.

Amino acid imbalance in ruminant lambs

1978 ◽  
Vol 29 (6) ◽  
pp. 1263 ◽  
Author(s):  
AR Egan ◽  
QR Rogers
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Essential Amino Acid ◽  
Essential Amino Acids ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Physiological Capacity ◽  
Mineral Mixture ◽  
Amino Acid Imbalance ◽  
Plasma Amino Acid Concentration

In a series of 14 experiments young Merino x Dorset Horn or Merino x Suffolk wethers were fed on wheaten straw or wheaten hay supplemented with a mineral mixture and, in some cases, urea and/or molasses. The diets were contrived to provide between 8 and 12% of digestible energy as protein digested in the intestines. A mixture of amino acids estimated to provide suitable proportions of essential amino acids and adequate non-essential amino acids was developed. With each diet, either the complete amino acid mixture, or a mixture from which one essential amino acid was excluded (imbalanced mixture), was infused per abomasum. In several experiments feed intake was depressed by imbalanced mixtures in which methionine, threonine, isoleucine and lysine were the respective deletions from the mixture, but was elevated by the infusion of the complete amino acid mixture. In each experiment an imbalanced infusion resulted in a decrease in plasma concentration of that amino acid excluded from the mixture to levels only 15–50% of control (pre-infusion) levels. All other essential amino acids were increased in concentration in plasma, reaching 1.5 to 6 times the concentrations in pre-infusion conditions. Infusions of greater amounts of amino acids resulted in greater changes in the plasma amino acid concentration. These results indicated that, although ruminant lambs ingesting herbage diets are unlikely to be subjected to an effective amino acid imbalance, they have the physiological capacity to respond to amino acid imbalances. This needs to be considered when rumen bypass of amino acids or proteins is being considered in practical or experimental circumstances.

Effect of amino acid meals on hepatic alpha-aminoisobutyrate transport and cyclic AMP

1975 ◽  
Vol 228 (5) ◽  
pp. 1606-1614 ◽  
Author(s):  
JK Tews ◽  
NW Colosi ◽  
AE Harper
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cyclic Amp ◽  
Casein Hydrolysate ◽  
Essential Amino Acids ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Dietary Amino Acids ◽  
Force Feeding ◽  
Dispensable Amino Acids

Within 1.5 h after force-feeding rats one meal of enzymatic hydrolysates of casein, gelatin, lactalbumin, or yeast, alpha-aminoisobutyric acid (AIB) transport in liver slices was stimulated two- to threefold. A complete amino acid mixture also increased AIB transport. Of the 15 amino acids or derivatives tested individually, the dispensable amino acids, especially glycine and alanine, were more stimulatory than the essential amino acids; feeding a mixture of amino acids lacking glycine and alanine increased AIB uptake only slightly. The effects were significantly greater in meal-fed than in ad libitum-fed rats. Increased hepatic concentrations of cyclic AM were usually associated with the increase in AIB transport. Feeding glucose inhibited the increases in transport and cyclic AMP concentration induced by casein hydrolysate or in the stimulation of AIB transport by dietary amino acids. The increases in AIB uptake appeared unrelated to the exchange of endogenous amino acids with medium AIB.

scholarly journals PLASMA PROTEIN AND HEMOGLOBIN PRODUCTION

1947 ◽  
Vol 85 (3) ◽  
pp. 243-265 ◽  
Author(s):  
F. S. Robscheit-Robbins ◽  
L. L. Miller ◽  
G. H. Whipple
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Plasma Protein ◽  
Nitrogen Balance ◽  
Essential Amino Acids ◽  
Amino Acid Mixture ◽  
Blood Protein ◽  
Acid Mixture ◽  
Amino Acid Mixtures ◽  
Urinary Nitrogen

Given healthy dogs fed abundant iron and protein-free or low protein diets with sustained anemia and hypoproteinemia, we can study the capacity of these animals to produce simultaneously new hemoglobin and plasma protein. Reserve stores of blood protein-building materials are measurably depleted and levels of 6 to 8 gm. per cent for hemoglobin and 4 to 5 gm. per cent for plasma protein can be maintained for weeks or months depending upon the intake of food proteins or amino acid mixtures. These dogs are very susceptible to infection and various poisons. Dogs tire of these diets and loss of appetite terminates many experiments. Under these conditions (double depletion) standard growth mixtures of essential amino acids are tested to show the response in blood protein output and urinary nitrogen balance. As a part of each tabulated experiment one of the essential amino acids is deleted from the complete growth mixture to compare such response with that of the whole mixture. Methionine, threonine, phenylalanine, and tryptophane when singly eliminated from the complete amino acid mixture do effect a sharp rise in urinary nitrogen. This loss of urinary nitrogen is corrected when the individual amino acid is replaced in the mixture. Histidine, lysine, and valine have a moderate influence upon urinary nitrogen balance toward nitrogen conservation. Leucine, isoleucine, and arginine have minimal or no effect upon urinary nitrogen balance when these individual amino acids are deleted from the complete growth mixture of amino acids during 3 to 4 week periods. Tryptophane and to a less extent phenylalanine and threonine when returned to the amino acid mixture are associated with a conspicuous preponderance of plasma protein output over the hemoglobin output (Table 4). Arginine, lysine, and histidine when returned to the amino acid mixture are associated with a large preponderance of hemoglobin output. Various amino acid mixtures under these conditions may give a positive urinary nitrogen balance and a liberal output of blood proteins but there is always weight loss, however we may choose to explain this loss. These experiments touch on the complex problems of parenteral nutrition, experimental and clinical.

scholarly journals Protein reserves and muscle constituents of protein-depleted and repleted cocks

1967 ◽  
Vol 21 (3) ◽  
pp. 661-670 ◽  
Author(s):  
John H. Ashley ◽  
Hans Fisher
Keyword(s):  
Amino Acids ◽  
Body Weight ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Essential Amino Acid ◽  
Essential Amino Acids ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Fish Protein

1. Body-weight changes and nitrogen balance were studied, together with the concentration of various nitrogenous muscle components, in adult cocks before and after a 6-day period on a N-free diet and again after a 16-day repletion period on diets supplying various amounts and types of dietary N.2. In the first experiment a comparison was made during the repletion period between a fish-protein supplement and a supplement of glycine + glutamic acid added to an essential amino acid mixture.3. During the depletion period the muscle concentration of RNA, DNA and of two transaminase enzymes decreased significantly; during the repletion period these components increased again significantly, and usually to levels greater than the pre-depletion concentration. There were no differences in these responses obtained during repletion with the two N supplements, although the cocks given the glycine–glutamic acid supplement differed from those receiving fish protein in being in Negative N balance and in losing body-weight during the repletion period.4. In the second experiment one group of depleted cocks was given an essential amino acid mixture alone as the dietary N source and a second group this mixture supplemented by aspartic acid.5. A decrease in RNA and in the transaminase enzymes during depletion was followed by a significant increase during repletion, but the increase was greater for the group receiving the aspartic acid than for that receiving only the essential amino acid mixture.6. It was concluded that adding non-essential amino acids to a maintenance mixture of essential amino acids will permit greater repletion in mature cocks.7. The fluctuations in concentration of RNA and of certain enzymes with dietary protein supply may well be controlling factor in the regulation of N losses and accretions during protein deficiency and sufficiency.5. The relative constancy of muscle DNA in contrast to the fluctuations in other nitrogenous muscle constituents provides additional support for the concept of protein reserves.

Influence of Dietary Amino Acids on Pancreatic Enzymes

1957 ◽  
Vol 191 (1) ◽  
pp. 71-74 ◽  
Author(s):  
S. S. Hong ◽  
D. F. Magee
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Enzyme Activities ◽  
Protease Activity ◽  
Essential Amino Acids ◽  
Amino Acid Mixture ◽  
Lipase Production ◽  
Acid Mixture ◽  
Casein Diet ◽  
Dietary Amino Acids

Rats were fed a low casein diet to which was added either single dl-amino acids to make 1% of the diet or supplements of dl essential amino acids equivalent proportionally and in total amount to an extra 8% casein. Glycine was added to substitute for the nonessential acids in casein. In six groups of rats this supplement was lacking in pairs of essential amino acids previously found to stimulate protease and lipase production. The pairs were made up of all possible combinations of the four acids in question. Threonine addition reduced all enzyme activities. Threonine removal increased protease activity. Arginine and histidine additions increased protease and lipase respectively. The complete amino acid supplement reduced protease below the control as did the supplement lacking in methionine and phenylalanine. No activity was increased by any amino acid mixture supplement. Lipase and amylase were unchanged by the mixtures except for an amylase depression in the group receiving a supplement lacking isoleucine and valine.

Protein value and amino-acid balance of condensed herring solubles and spontaneously heated herring meal. Chick experiments

1958 ◽  
Vol 51 (2) ◽  
pp. 164-176 ◽  
Author(s):  
B. Laksesvela
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Essential Amino Acids ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Meal Protein ◽  
Amino Acid Balance ◽  
Microbiological Assays

1. In a series of tests chicks were fed up to 4 weeks of age on a ‘purified’ diet supplemented with 10% of protein from either herring meal or condensed herring solubles.2. The solubles alone appeared of negligible value as a protein source, but certain mixtures of solubles and meal protein proved superior to meal alone, although the levels of the essential amino acids plus cystine and tyrosine were lower in the mixture than in meal alone. The supplementary effect may possibly be due to changes in the aminoacid ratio or balance.3. Only tryptophan improved growth and viability when free amino acids were added singly to the solubles. Simultaneous supply of all 10 essential amino acids elevated growth to about 80% of that on meal alone. A combination of tryptophan, isoleucine, histidine and phenylalanine appeared nearly as effective as the 10. Depressant effects of free amino acids at the low levels used were also met with. The chick results followed closely the predictions made from the results of microbiological assays of the amino-acid composition of the solubles, and these were in conformity with the composition of the ‘ideal’ amino-acid mixture for chicks proposed by Fisher & Johnson (1957).4. The small weight gains of the chicks on solubles alone consisted largely of water rather than true tissue. Appetite appeared to be governed by the balance of amino acids, this appearing to be more important than the absolute levels fed. This applied to diets with heated meal as well as the solubles.

scholarly journals Effect of co-ingestion of amino acids with rice on glycaemic and insulinaemic response

2015 ◽  
Vol 114 (11) ◽  
pp. 1845-1851 ◽  
Author(s):  
Yean Yean Soong ◽  
Joseph Lim ◽  
Lijuan Sun ◽  
Christiani Jeyakumar Henry
Keyword(s):  
Amino Acids ◽  
Blood Glucose ◽  
Amino Acid ◽  
Glycaemic Index ◽  
Amino Acid Mixture ◽  
Postprandial Blood Glucose ◽  
Acid Mixture ◽  
White Rice ◽  
Amino Acid Mixtures

AbstractConsumption of high glycaemic index (GI) and glycaemic response (GR) food such as white rice has been implicated in the development of type 2 diabetes. Previous studies have reported the ability of individual amino acids to reduce GR of carbohydrate-rich foods. Because of the bitter flavour of amino acids, they have rarely been used to reduce GR. We now report the use of a palatable, preformed amino acid mixture in the form of essence of chicken. In all, sixteen healthy male Chinese were served 68 or 136 ml amino acid mixture together with rice, or 15 or 30 min before consumption of white rice. Postprandial blood glucose and plasma insulin concentrations were measured at fasting and every 15 min after consumption of the meal until 60 min after the consumption of the white rice. Subsequent blood samples were taken at 30-min intervals until 210 min. The co-ingestion of 68 ml of amino acid mixture with white rice produced the best results in reducing the peak blood glucose and GR of white rice without increasing the insulinaemic response. It is postulated that amino acid mixtures prime β-cell insulin secretion and peripheral tissue uptake of glucose. The use of ready-to-drink amino acid mixtures may be a useful strategy for lowering the high-GI rice diets consumed in Asia.

Olfactory Conditioning by Association with Histidine-Free or Balanced Amino Acid Loads in Rats†

1973 ◽  
Vol 25 (3) ◽  
pp. 354-359 ◽  
Author(s):  
P. C. Simson ◽  
D. A. Booth
Keyword(s):  
Amino Acid ◽  
Food Intake ◽  
Amino Acid Mixture ◽  
Conditioned Aversion ◽  
Acid Mixture ◽  
Olfactory Conditioning ◽  
Conditioned Preference ◽  
Gastric Intubation ◽  
Protein Free Diet

An histidine-devoid but otherwise balanced amino acid mixture depressed food intake from 2 hr after its gastric intubation. It induced conditioned aversion to an odour incorporated in a protein-free diet presented for 6 h following intubation. In other rats, a balanced amino acid mixture established conditioned preference for odour presented in the same diet for 6 h following intubation. The degree of preference was considerably less than the degree of aversion.

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