Influence of protein and amino acids on food intake in the rat

1965 ◽  
Vol 209 (3) ◽  
pp. 479-483 ◽  
Author(s):  
Ronald M. Krauss ◽  
Jean Mayer
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Intake ◽  
Protein Intake ◽  
Safety Valve ◽  
Constant Amount ◽  
Catabolic Activity ◽  
Low Protein ◽  
Amino Acid Intake ◽  
Hypothalamic Mechanism

The depression of food intake by high levels of dietary protein and by an excess of l-leucine in a low-protein diet was found to be independent of the presence of the hypothalamic mechanism regulating food intake. At extremely high levels of protein or amino acid intake, the amount of diet ingested was restricted to a similar level in normal and hyperphagic rats. The fact that hyperphagic rats consumed a relatively constant amount of casein in diets containing 60– 90% of protein suggested the possibility that a physiological "safety valve" operated to limit dietary intake so that protein intake did not exceed a certain threshold. An accumulation of amino acids that could not be metabolized or diverted into protein synthesis may have mediated the appetite effects. This suggestion was consistent with the finding that prefeeding high levels of protein (40 or 60% of casein), a procedure which is known to enhance amino acid catabolic activity, temporarily eliminated the appetite depression normally caused by subsequent ingestion of a high-leucine diet.

scholarly journals No protein intake compensation for insufficient indispensable amino acid intake with a low-protein diet for 12 days

2014 ◽  
Vol 11 (1) ◽  
pp. 38 ◽  
Author(s):  
Eveline A Martens ◽  
Sze-Yen Tan ◽  
Richard D Mattes ◽  
Margriet S Westerterp-Plantenga
Keyword(s):  
Amino Acid ◽  
Protein Intake ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Acid Intake ◽  
Low Protein ◽  
Indispensable Amino Acid ◽  
Amino Acid Intake

scholarly journals Carotid or jugular amino acid infusions and food intake in the cockerel

1979 ◽  
Vol 41 (1) ◽  
pp. 157-162 ◽  
Author(s):  
G. Tobin ◽  
K. N. Boorman
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Intake ◽  
Carotid Arteries ◽  
Marked Effect ◽  
Protein Diet ◽  
Jugular Veins ◽  
Low Protein ◽  
Food Intake Regulation ◽  
Intake Regulation

1. Infusions of histidine into the carotid arteries of cockerels receiving a histidine-limiting, imbalanced diet caused an increase in food intake, whereas similar infusions into the jugular veins did not.2. Infusions of lysine into the carotid arteries or jugular veins of young cockerels receiving a balanced, low-protein diet caused decreases in food intake. There was evidence of a more marked effect of carotid infusion.3. The mechanisms of food intake regulation by amino acids in mammals are applicable to birds and excesses of single amino acids do seem to affect food intake directly.

scholarly journals A vailability to pigs of amino acids in cereal grains

1981 ◽  
Vol 46 (1) ◽  
pp. 149-158 ◽  
Author(s):  
M. R. Taverner ◽  
I. D. Hume ◽  
D. J. Farrell
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Dietary Fibre ◽  
Acid Output ◽  
Low Protein ◽  
Dietary Amino Acid ◽  
Amino Acid Intake ◽  
Endogenous Amino Acid

1. Endogenous levels of amino acids in ileal digests were determined as the output from pigs given protein-free diets and by extrapolation to zero intake of linear regressions of ileal amino acid output v. dietary amino acid intake. The protein-free diets included 0 or 50 g cellulose/kg and extrapolations were made from two series of four diets which contained graded levels of wheat or barley as the only source of protein. Within each series, dietary fibre level (mg/g) was maintained at approximately 140 or 190 neutral-detergent fibre (NDF) respectively. Endogenous amino acid levels in faeces were also determined.2. Endogenous amino acid output in faeces was linearly related to dietary fibre level; endogenous ileal output increased with dietary fibre up to approximately 100 mg NDF/g, after which endogenous output no longer increased.3. The amino acid composition of endogenous ileal protein varied little among levels of output and among different experiments. The composition appears to be determined by the predominance of mucin protein, the slow absorption of some amino acids and the methods commonly used to measure output. The very high levels of proline and glycine in ileal digesta seemed characteristic only of protein-free and low-protein diets.4. The amino acid composition of endogenous faecal protein also varied little among different estimates, but was considerably different from that of endogenous ileal protein. Furthermore, the similarity of bacterial and faecal proteins suggested that much of the endogenous faecal protein was of bacterial origin.

scholarly journals Biochemical characteristics of different forms of protein-energy malnutrition: an experimental model using young rats

1977 ◽  
Vol 37 (1) ◽  
pp. 1-21 ◽  
Author(s):  
C. R. C. Heard ◽  
Sylvia M. Frangi ◽  
Pauline M. Wright ◽  
P. R. McCartney
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Intake ◽  
Glucose Tolerance ◽  
Plasma Protein ◽  
Alanine Aminotransferase ◽  
Normal Values ◽  
Liver Fat ◽  
Insulin Levels ◽  
Low Protein

1. In three separate experiments, four groups of five to eight young male rats were fed either (i) a high-protein diet, for which the net dietary protein: total metabolizable energy ratio (NDp:E) was 0.1 (HP diet); or (ii) a low-protein diet, for which NDP:E was 0.04 (LP diet). In both these groups, food intake was ad lib In group (iii) the HP diet was given in an amount approximately equal to that taken by the LP group fed ad lib. (HP-restricted). In group (iv) rats were fasted for 48 h after receiving the HP diet (HP-fasted). Each experiment lasted 4 weeks.2. In the LP and HP-restricted groups, food intake was about 50% of that of the HP rats, while body-weight, after 4 weeks on diet was about 35% and 55% of that of HP rats, for LP and HP-restricted respectively. Both groups of malnourished rats gained some weight during the experiment.3. Measurements of oral glucose tolerance and plasma insulin levels were made in the fourth week. LP and HP-restricted rats both showed low fasting insulin levels and low insulin to glucose ratios during the glucose tolerance tests; the LP rats were more seriously affected.4. At the end of the fourth week the rats were killed and blood, liver and gastrocnemius muscle were analysed. LP rats showed specifically and consistently low values for haemoglobin and plasma protein concentration, and low activities of hepatic glucose-6-phosphatase (EC 3.1.3.9) and of alanine aminotransferase (EC 2.6.1.2) in liver and muscle. The activity of hepatic aspartate aminotransferase (EC 2.6.1.1) was, if anything, increased. The plasma amino acid concentrations and ratios showed a specific fall in branched-chain amino acids. Liver fat concentration was consistently elevated. The HP-restricted rats had normal values for haemoglobin, plasma protein and liver fat, and near-normal values for plasma amino acids. Hepatic alanine aminotransferase showed increased activity compared with HP rats, but muscle alanine aminotransferase showed reduced activity. The HP-fasted rats had increased haemoglobin, plasma protein and liver fat concentration, and very low liver glycogen concentrations. Hepatic alanine aminotransferase activity was elevated. Plasma alanine concentration was specifically reduced.5. The results are consistent with suppression of gluconeogenesis, liver dysfunction and essential amino acid deprivation in LP rats. These biochemical changes found in rats on a low intake of a diet of low protein and high carbohydrate value are similar to those found in kwashiorkor. An equally low intake of a diet of good protein value (HP-restricted) led to marginally better growth, accompanied by biochemical signs of increased gluconeogenesis, analogous to those reported for nutritional marasmus. This nutritional state was not biochemically identical with that of acute fasting.6. The results are discussed in terms of the consistency of the rat model, and its contribution to understanding biochemical changes found in infant malnutrition.

Dietary intake of tryptophan tied emotion-related impulsivity in humans

2019 ◽  
pp. 1-8 ◽  
Author(s):  
Florian Javelle ◽  
Descartes Li ◽  
Philipp Zimmer ◽  
Sheri L. Johnson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Intake ◽  
Essential Amino Acid ◽  
Food Habits ◽  
Psychological Disorder ◽  
Serotonin Synthesis ◽  
Amino Acid Tryptophan ◽  
Pass Through ◽  
Three Factor

Abstract. Emotion-related impulsivity, defined as the tendency to say or do things that one later regret during periods of heightened emotion, has been tied to a broad range of psychopathologies. Previous work has suggested that emotion-related impulsivity is tied to an impaired function of the serotonergic system. Central serotonin synthesis relies on the intake of the essential amino acid, tryptophan and its ability to pass through the blood brain barrier. Objective: The aim of this study was to determine the association between emotion-related impulsivity and tryptophan intake. Methods: Undergraduate participants (N = 25, 16 women, 9 men) completed a self-rated measure of impulsivity (Three Factor Impulsivity Index, TFI) and daily logs of their food intake and exercise. These data were coded using the software NutriNote to evaluate intakes of tryptophan, large neutral amino acids, vitamins B6/B12, and exercise. Results: Correlational analyses indicated that higher tryptophan intake was associated with significantly lower scores on two out of three subscales of the TFI, Pervasive Influence of Feelings scores r =  –.502, p < . 010, and (lack-of) Follow-Through scores, r =  –.407, p < . 050. Conclusion: Findings provide further evidence that emotion-related impulsivity is correlated to serotonergic indices, even when considering only food habits. It also suggests the need for more research on whether tryptophan supplements might be beneficial for impulsive persons suffering from a psychological disorder.

scholarly journals Are Dietary Amino Acids or Protein Quality Associated with Infant Length Gain from 6 to 12 Months in Rural Malawi? (P10-010-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Andrew Matchado ◽  
Kathryn Dewey ◽  
Christine Stewart ◽  
Per Ashorn ◽  
Ulla Ashorn ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Breast Milk ◽  
Protein Quality ◽  
Complementary Food ◽  
Complementary Foods ◽  
Acid Intake ◽  
Dietary Amino Acid ◽  
Amino Acid Intake ◽  
Length Gain

Abstract Objectives 1) to estimate the probability of inadequate amino acid intake among infants 9–10 months of age in rural Malawi 2) to evaluate whether dietary amino acid intake or protein quality are associated with length gain from 6 to 12 months of age Methods We assessed total amino acid intake from breast milk and complementary foods in 285 infants. Breast milk intake and complementary foods were estimated using dose-to-mother deuterium oxide dilution method and repeat 4-pass interactive 24-hour recall interviews, respectively. Amino acid composition values were taken from FAO human milk profile, Tanzania Food Composition table and International Minilist. Protein quality was estimated using Digestible Indispensable Amino Acid Score (DIAAS). Probability of intake below Estimated Average Requirement (EAR) for each amino acid was estimated using National Cancer Institute (NCI) method. We estimated protein quality of complementary food using median DIAAS. We assumed a DIAAS of ≥0.75 to represent a diet or food with good protein quality. Relationships between amino acid intake or protein quality with length gain were assessed using regression models. Length was measured at 6 and 12 months of age and length for age z-score (LAZ) velocity was calculated (ΔLAZ/months). Results The probability of inadequate amino acid intake from breast milk and complementary food that included a lipid-based nutrient supplement (LNS) was 3% for lysine, 0% for tryptophan, threonine, valine, histidine, isoleucine, leucine, sulfur containing amino acids (SAA), and aromatic amino acids (AAA). Without LNS, the probability was 7% for lysine and 0–2% for the other amino acids. The median (interquartile range) DIAAS for complementary food with and without LNS was 0.70 (0.28) and 0.64 (0.32), respectively. Dietary amino acid intake and protein quality were not significantly associated with length gain velocity from 6 to 12 months even after adjusting for confounding factors. Conclusions The prevalence of inadequate amino acid intake in 9–10 months old infants in rural Malawi is very low. However, in conditions of frequent clinical or sub-clinical infections this situation may be different. Linear growth at 6–12 months does not appear to be limited by dietary amino acid intake or protein quality in this setting. Funding Sources The Bill & Melinda Gates Foundation.

scholarly journals Performance of Broilers Fed Low Protein Diets with Lysine and Methionine Supplements

2006 ◽  
Vol 6 (1) ◽  
pp. 47-59
Author(s):  
Nancy Montilla ◽  
◽  
Lolito Bestil ◽  
Sulpecio Bantugan ◽  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Content ◽  
High Protein Diet ◽  
Protein Diet ◽  
Amino Acid Supplementation ◽  
Feed Conversion ◽  
Broiler Performance ◽  
Acid Supplementation ◽  
Low Protein

A feeding trial with broilers was conducted to evaluate the effects of amino acids (lysine and methionine) supplementation of diets low in protein content on the voluntary intake, feed conversion efficiency, broiler performance, and cost and return of broiler production. Results showed cumulative voluntary feed intake was not significantly affected by lowering the protein content of the diet. Cumulative weight gain of broilers was lower with diet when supplemented iwht lysine and methionine to meet requirements. Birds fed with diets low in protein has less efficient feed converstion, but became comparable with those receiveing diets high in protein when supplemented with amino acids. Feed cost per kilogram broiler produced was not significantly affected by diets used in the study, although the low-protien diet with amino acid supplement had the lowest values. In terms of return above feed and chick cost, broilers fed with high-protein diet had the greatest value, but not significantly different from birds fed with low-protien diet with amino acid supplementation which gave about P10 per bird higher returns than those fed low-protein diet without amino acid supplementation.

Food Intake Regulation: Amino Acid Toxicity and Changes in Rat Brain and Plasma Amino Acids

1973 ◽  
Vol 103 (4) ◽  
pp. 608-617 ◽  
Author(s):  
Y. Peng ◽  
J. Gubin ◽  
A. E. Harper ◽  
M. G. Vavich ◽  
A. R. Kemmerer
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Intake ◽  
Rat Brain ◽  
Plasma Amino Acids ◽  
Food Intake Regulation ◽  
Acid Toxicity ◽  
Intake Regulation
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