scholarly journals Carbohydrate metabolism during prolonged exercise and recovery: interactions between pyruvate dehydrogenase, fatty acids, and amino acids

2006 ◽  
Vol 100 (6) ◽  
pp. 1822-1830 ◽  
Author(s):  
Marina Mourtzakis ◽  
Bengt Saltin ◽  
Terry Graham ◽  
Henriette Pilegaard
Keyword(s):  
Amino Acids ◽  
Fatty Acid ◽  
Amino Acid ◽  
Pyruvate Dehydrogenase ◽  
Prolonged Exercise ◽  
Carbohydrate Oxidation ◽  
Total Amino Acid ◽  
Acid Uptake ◽  
Flow Measurements ◽  
Early Exercise

During prolonged exercise, carbohydrate oxidation may result from decreased pyruvate production and increased fatty acid supply and ultimately lead to reduced pyruvate dehydrogenase (PDH) activity. Pyruvate also interacts with the amino acids alanine, glutamine, and glutamate, whereby the decline in pyruvate production could affect tricarboxycylic acid cycle flux as well as gluconeogenesis. To enhance our understanding of these interactions, we studied the time course of changes in substrate utilization in six men who cycled at 44 ± 1% peak oxygen consumption (mean ± SE) until exhaustion (exhaustion at 3 h 23 min ± 11 min). Femoral arterial and venous blood, blood flow measurements, and muscle samples were obtained hourly during exercise and recovery (3 h). Carbohydrate oxidation peaked at 30 min of exercise and subsequently decreased for the remainder of the exercise bout ( P < 0.05). PDH activity peaked at 2 h of exercise, whereas pyruvate production peaked at 1 h of exercise and was reduced (∼30%) thereafter, suggesting that pyruvate availability primarily accounted for reduced carbohydrate oxidation. Increased free fatty acid uptake ( P < 0.05) was also associated with decreasing PDH activity ( P < 0.05) and increased PDH kinase 4 mRNA ( P < 0.05) during exercise and recovery. At 1 h of exercise, pyruvate production was greatest and was closely linked to glutamate, which was the predominant amino acid taken up during exercise and recovery. Alanine and glutamine were also associated with pyruvate metabolism, and they comprised ∼68% of total amino-acid release during exercise and recovery. Thus reduced pyruvate production was primarily associated with reduced carbohydrate oxidation, whereas the greatest production of pyruvate was related to glutamate, glutamine, and alanine metabolism in early exercise.

Composition of amino acids and fatty acids on Luwak coffee processing

Food Research ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 60-64
Author(s):  
Fitri ◽  
A. Laga ◽  
Z. Dwyana ◽  
A.B. Tawali
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Amino Acid ◽  
Acid Content ◽  
Green Bean ◽  
Total Amino Acid ◽  
Coffee Bean ◽  
Roasted Coffee ◽  
Coffee Beans

The processing carried out on coffee beans such as fermentation and roasting can affect the contents of amino and fatty acids of coffee beans. This study aimed to determine the amount of amino acid and fatty acid content in Luwak coffee bean during processing. The amino acids of coffee were analyzed using HPLC, while fatty acids of coffee were analyzed using GC-MS. The results showed a change in total amino acid content in raw coffee bean (3.04%), green bean coffee (6.93%), and roasted coffee (6.83%). The total fatty acid of raw coffee bean (1199.86 mg/100 g), green bean coffee (3147.56 mg/100 g), and roasted coffee (6282.4 mg/100 g) also experienced significant changes

scholarly journals Plasma amino acid concentrations in pregnant rats and in 21-day foetuses

1977 ◽  
Vol 166 (1) ◽  
pp. 49-55 ◽  
Author(s):  
A Palou ◽  
L Arola ◽  
M Alemany
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Plasma Amino Acid ◽  
Female Rats ◽  
Total Amino Acid ◽  
Acid Uptake ◽  
Pregnant Rats ◽  
Foetal Growth ◽  
Amino Acid Concentrations ◽  
Concentration Ratios

Plasma amino acid concentrations were determined in virgin female rats, in pregnant rats (12 and 21 days after impregnation) and in 21-day foetuses. The total amino acid concentration in plasma decreases significantly with pregnancy, being lower at 12 than at 21 days. Alanine, glutamine+glutamate and other ‘gluconeogenic’ amino acids decrease dramatically by mid-term, but regain their original concentrations at the end of the pregnancy. With most other amino acids, mainly the essential ones, the trend is towards lower concentrations which are maintained throughout pregnancy. These data agree with known nitrogen-conservation schemes in pregnancy and with the important demands on amino acids provoked by foetal growth. In the 21-day foetuses, concentrations of individual amino acids are considerably higher than in their mothers, with high plasma foetal/maternal concentration ratios, especially for lysine, phenylalanine and hydroxy-proline, suggesting active protein biosynthesis and turnover. All other amino acids also have high concentration ratios, presumably owing to their requirement by the foetuses for growth. Alanine, glutamine+glutamate, asparagine+aspartate, glycine, serine and threonine form a lower proportion of the total amino acids in foetuses than in the virgin controls or pregnant rats, probably owing to their role primarily in energy metabolism in the adults. The results indicate that at this phase of foetal growth, the placental amino acid uptake is considerable and seems to be higher than immediately before birth.

3.1 The Nitrogen Supplied by and the Supplementation of Fresh or Grazed Forage

1982 ◽  
Vol 6 ◽  
pp. 53-66 ◽  
Author(s):  
D.J. Thomson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Crude Protein ◽  
Alimentary Tract ◽  
Metabolizable Energy ◽  
Total Amino Acid ◽  
Flow Measurements ◽  
Flow Rates ◽  
The Difference ◽  
Protein Supply

Forage contributes between 70 and 80% of the metabolizable energy (ME) and in excess of 70% of the protein consumed by ruminant livestock in the U.K. (Baker and Wilkins, 1975). The contribution from forage to the energy and protein consumed is highest for sheep and lowest for dairy cattle. For all classes of stock in the U.K., a major proportion of the nitrogen (N) or crude protein (CP) consumed is obtained from fresh or grazed forage.Research with fresh forage, both nutritional and production work, has been faced with the difficulty of measuring or estimating food intake by the animal while grazing. The measurement of protein supply from fresh or grazed forage is further made difficult as flow measurements throughout the alimentary tract are required. For forage, as with other foods given to ruminants, estimates of the supply of N or protein available to the animal are obtained from measurements of flow from the stomach or into the proximal duodenum and at the terminal ileum. The difference between these two flow rates, the disappearance of N, NAN (non-ammonia N) or AAN (amino acid N), is taken as the apparent absorption or supply of protein from the food. Values may be obtained for individual amino acids or for total amino acid N (TAAN).

Nitrogen handling in adult hypothalamic obese rats

1980 ◽  
Vol 238 (1) ◽  
pp. E32-E37
Author(s):  
C. Karakash ◽  
F. Rohner-Jeanrenaud ◽  
B. E. Hustvedt ◽  
B. Jeanrenaud
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ventromedial Hypothalamus ◽  
Total Amino Acid ◽  
Acid Uptake ◽  
Liver Protein ◽  
Urea Synthesis ◽  
Peripheral Tissues ◽  
Urea Production

Several aspects of nitrogen metabolism have been studied in adult nonhyperphagic, hyperinsulinemic, ventromedial hypothalamus (VMH)-lesioned rats. Ten days postoperatively, VMH-lesioned rats had high plasma levels of urea and low plasma tyrosine, while plasma alanine, glutamine, total amino acid, and protein levels were unaltered. Urea production and excretion were increased in VMH-lesioned rats. Increased urea synthesis could not be attributed to enhanced peripheral release of amino acids. In vitro, measurements of hepatic amino acid uptake and liver protein synthesis did not reveal any disturbances of these processes in VMH-lesioned rats. However, hepatic transamination and lipogenesis from amino acids were increased following VMH-lesions. In addition to the hyperinsulinemia previously reported to occur in nonhyperphagic VMH-lesioned rats, this study showed an increased glucagon secretion from perfused pancreases of these animals. These data together suggest that the excess of the two hormones at the portal vein of VMH-lesioned rats would favor uptake and deamination of amino acids, their diversion to lipid synthesis and possibly other pathways, with consequent increase in urea production and reduced supply of amino acids to peripheral tissues available for nitrogen retention.

Leg Metabolism of Amino Acids and Ammonia in Patients with Chronic Renal Failure

1985 ◽  
Vol 69 (2) ◽  
pp. 143-151 ◽  
Author(s):  
Giacomo Deferrari ◽  
Giacomo Garibotto ◽  
Cristina Robaudo ◽  
Alberto Canepa ◽  
Serena Bagnasco ◽  
...  
Keyword(s):  
Amino Acids ◽  
Renal Failure ◽  
Chronic Renal Failure ◽  
Amino Acid ◽  
Total Amino Acid ◽  
Acid Uptake ◽  
Peripheral Tissues ◽  
Amino Acid Release ◽  
Arterial Blood ◽  
Acid Release

1. Leg metabolism of amino acids and ammonia in the postabsorptive state was evaluated in 10 patients with chronic renal failure (CRF) and in 10 patients with normal renal function (controls) by measuring the arterial-femoral venous (A-FV) differences for free amino acids and ammonia. 2. Total amino acid release from the leg and alanine and glutamine release, which accounts for the greatest amount of the total amino acid release, are similar in patients and controls. Total amino acid uptake from the arterial blood and glutamate uptake, which is the amino acid extracted at the highest rate, are comparable in both groups. Taken together these data, in addition to the similarity of A-FV differences for proteolytic markers, namely tyrosine, phenylalanine and histidine, suggest that protein breakdown in peripheral tissues is not increased in patients with CRF. 3. In CRF selective metabolic abnormalities for some amino acids are evident. Whilst only the A-FV differences for valine, leucine and isoleucine are decreased, additional alterations are observed by relating the A-FV difference for each amino acid to that of proteolytic markers. Such a procedure demonstrates that in CRF histidine release relative to that of proteolytic markers is reduced, whereas proline and arginine release is increased. 4. In CRF the reduced release of some amino acids, mainly branched-chain amino acids, by the leg probably affects the pattern of circulating amino acids. 5. Finally, both in patients and in controls a significant uptake of ammonia is observed; the ammonia uptake is related to arterial levels of this metabolite, confirming the role of peripheral tissues in removing ammonia from circulation.

scholarly journals Basil as Secondary Crop in Cascade Hydroponics: Exploring Salinity Tolerance Limits in Terms of Growth, Amino Acid Profile, and Nutrient Composition

Horticulturae ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 203
Author(s):  
Denisa Avdouli ◽  
Johannes F. J. Max ◽  
Nikolaos Katsoulas ◽  
Efi Levizou
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Salinity Tolerance ◽  
Total Concentration ◽  
Amino Acid Profile ◽  
Total Amino Acid ◽  
Cascade System ◽  
Hydroponic System ◽  
Salinity Levels ◽  
Use Efficiency

In a cascade hydroponic system, the used nutrient solution drained from a primary crop is directed to a secondary crop, enhancing resource-use efficiency while minimizing waste. Nevertheless, the inevitably increased EC of the drainage solution requires salinity-tolerant crops. The present study explored the salinity-tolerance thresholds of basil to evaluate its potential use as a secondary crop in a cascade system. Two distinct but complemented approaches were used; the first experiment examined basil response to increased levels of salinity (5, 10 and 15 dS m−1, compared with 2 dS m−1 of control) to identify the limits, and the second experiment employed a cascade system with cucumber as a primary crop to monitor basil responses to the drainage solution of 3.2 dS m−1. Growth, ascorbate content, nutrient concentration, and total amino acid concentration and profile were determined in both experiments. Various aspects of basil growth and biochemical performance collectively indicated the 5 dS m−1 salinity level as the upper limit/threshold of tolerance to stress. Higher salinity levels considerably suppressed fresh weight production, though the total concentration of amino acids showed a sevenfold increase under 15 dS m−1 and 4.5-fold under 5 and 10 dS m−1 compared to the control. The performance of basil in the cascade system was subject to a compromise between a reduction of fresh produce and an increase of total amino acids and ascorbate content. This outcome indicated that basil performed well under the conditions and the system employed in the present study, and might be a good candidate for use as a secondary crop in cascade-hydroponics systems.

Gamma-Glutamyl-Amino Acids as Signals for the Hormonal Regulation of Amino Acid Uptake by the Mammary Gland of the Lactating Rat

Neonatology ◽  
1985 ◽  
Vol 48 (4) ◽  
pp. 250-256 ◽  
Author(s):  
Juan R. Viña ◽  
Inmaculada R. Puertes ◽  
Juan B. Montoro ◽  
Guillermo T. Saez ◽  
José Viña
Keyword(s):  
Amino Acids ◽  
Mammary Gland ◽  
Amino Acid ◽  
Hormonal Regulation ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Gamma Glutamyl

scholarly journals Novel role of the ER/SR Ca2+ sensor STIM1 in the regulation of cardiac metabolism

2019 ◽  
Vol 316 (5) ◽  
pp. H1014-H1026 ◽  
Author(s):  
Helen E. Collins ◽  
Betty M. Pat ◽  
Luyun Zou ◽  
Silvio H. Litovsky ◽  
Adam R. Wende ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Fatty Acid ◽  
Pyruvate Dehydrogenase ◽  
Glucose Utilization ◽  
Cardiac Metabolism ◽  
Mitochondrial Morphology ◽  
Acid Uptake ◽  
Stromal Interaction Molecule 1 ◽  
First Time

The endoplasmic reticulum/sarcoplasmic reticulum Ca2+ sensor stromal interaction molecule 1 (STIM1), a key mediator of store-operated Ca2+ entry, is expressed in cardiomyocytes and has been implicated in regulating multiple cardiac processes, including hypertrophic signaling. Interestingly, cardiomyocyte-restricted deletion of STIM1 (crSTIM1-KO) results in age-dependent endoplasmic reticulum stress, altered mitochondrial morphology, and dilated cardiomyopathy in mice. Here, we tested the hypothesis that STIM1 deficiency may also impact cardiac metabolism. Hearts isolated from 20-wk-old crSTIM1-KO mice exhibited a significant reduction in both oxidative and nonoxidative glucose utilization. Consistent with the reduction in glucose utilization, expression of glucose transporter 4 and AMP-activated protein kinase phosphorylation were all reduced, whereas pyruvate dehydrogenase kinase 4 and pyruvate dehydrogenase phosphorylation were increased, in crSTIM1-KO hearts. Despite similar rates of fatty acid oxidation in control and crSTIM1-KO hearts ex vivo, crSTIM1-KO hearts contained increased lipid/triglyceride content as well as increased fatty acid-binding protein 4, fatty acid synthase, acyl-CoA thioesterase 1, hormone-sensitive lipase, and adipose triglyceride lipase expression compared with control hearts, suggestive of a possible imbalance between fatty acid uptake and oxidation. Insulin-mediated alterations in AKT phosphorylation were observed in crSTIM1-KO hearts, consistent with cardiac insulin resistance. Interestingly, we observed abnormal mitochondria and increased lipid accumulation in 12-wk crSTIM1-KO hearts, suggesting that these changes may initiate the subsequent metabolic dysfunction. These results demonstrate, for the first time, that cardiomyocyte STIM1 may play a key role in regulating cardiac metabolism. NEW & NOTEWORTHY Little is known of the physiological role of stromal interaction molecule 1 (STIM1) in the heart. Here, we demonstrate, for the first time, that hearts lacking cardiomyocyte STIM1 exhibit dysregulation of both cardiac glucose and lipid metabolism. Consequently, these results suggest a potentially novel role for STIM1 in regulating cardiac metabolism.

scholarly journals Action of growth hormone in vitro on the net uptake and incorporation into protein of amino acids in muscle from intact rabbits given protein-deficient diets

1976 ◽  
Vol 35 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. R. Turner ◽  
P. J. Reeds ◽  
K. A. Munday
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Amino Acid ◽  
De Novo ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Amino Acid Incorporation ◽  
Acid Incorporation

1. Net amino acid uptake, and incorporation into protein have been measured in vitro in the presence and absence of porcine growth hormone (GH) in muscle from intact rabbits fed for 5 d on low-protein (LP), protein-free (PF) or control diets.2. In muscle from control and LP animals GH had no effect on the net amino acid uptake but stimulated amino acid incorporation into protein, although this response was less in LP animals than in control animals.3. In muscle from PF animals, GH stimulated both amino acid incorporation into protein and the net amino acid uptake, a type of response which also occurs in hypophysectomized animals. The magnitude of the effect of GH on the incorporation of amino acids into protein was reduced in muscle from PF animals.4. The effect of GH on the net amino acid uptake in PF animals was completely blocked by cycloheximide; the uptake effect of GH in these animals was dependent therefore on de novo protein synthesis.5. It is proposed that in the adult the role of growth hormone in protein metabolism is to sustain cellular protein synthesis when there is a decrease in the level of substrate amino acids, similar to that which occurs during a short-term fast or when the dietary protein intake is inadequate.

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