The Effect of Sodium Chloride on Proteolysis and on the Fate of Amino Acids Present in the Muscle of Codfish (Gadus callarias)

1959 ◽  
Vol 16 (5) ◽  
pp. 747-754
Author(s):  
E. Bilinski ◽  
H. Fougère
Keyword(s):  
Amino Acids ◽  
Sodium Chloride ◽  
Free Amino Acids ◽  
Free Amino ◽  
Muscle Protein ◽  
Chloride Content ◽  
Fish Muscle

The rate of proteolysis and the deamination of free amino acids in cod muscle treated with 4, 8, 12 and 16% sodium chloride varies with the sodium chloride content and temperature. Proteolysis of the fish muscle protein is completely inhibited at concentrations of 16 and 12% sodium chloride. Trimethylamine formation is inhibited by 16% sodium chloride for at least 15 days. Both inhibitions take place at either 15 or 25 °C. In salted muscle deamination can occur in the absence of trimethylamine formation. The reaction appears to be hardly influenced by salt. Indole formation is completely inhibited by 8% salt at either 15 or 25 °C.

Reproduction Versus Somatic Growth: Hormonal Control in Octopus Vulgaris

1978 ◽  
Vol 77 (1) ◽  
pp. 15-31 ◽  
Author(s):  
R. K. O'DOR ◽  
M. J. WELLS
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Muscle Protein ◽  
Somatic Growth ◽  
Hormonal Control ◽  
Gland Secretion ◽  
Total Amino Acid ◽  
Octopus Vulgaris ◽  
Precocious Maturity

Octopus vulgaris can be forced into precocious maturity by removal of the subpedunculate lobe from the brain, an operation that releases the optic glands from inhibition, and allows them to secrete a gonadotropin. 14C-leucine was injected into the bloodstream of immature animals and its subsequent incorporation into muscle protein followed by taking successive samples from the arms. The optic glands were then activated, and a further injection of 3H-leucine given and followed by means of further arm samples. Optic gland secretion suppresses protein synthesis in the muscles. This is associated with an increase in the total amino acid pool in the muscles and with a considerable increase in the concentration of free amino acids circulating in the blood. If an ovary is present these events are associated with a rapid growth of the ovary and its ducts, and a loss of weight elsewhere. In ovariectomized animals the ducts grow, but there is no yolk to absorb the large pool of free amino acids, and the animals gain weight by osmotic uptake of water into the muscles. The developing ovary may produce a hormone that increases the release of amino acids from muscle, since the concentration circulating in the blood of intact animals remains at least as high as in ovariectomized octopuses, despite the demands of the developing ovary. These matters are discussed in relation to other evidence for a gonadial hormone and in relation to the ‘self-destruct’ effect of the optic gland secretion in determining the post-reproductive death of octopuses.

scholarly journals Studies of the chemical composition of a healing skin wound in rats, and of the concentrations of some constituents of tissues distant from the healing wound

1967 ◽  
Vol 102 (3) ◽  
pp. 767-773 ◽  
Author(s):  
J Candlish ◽  
N. Chandra
Keyword(s):  
Amino Acids ◽  
Ascorbic Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Muscle Protein ◽  
Skin Wound ◽  
Neutral Salt ◽  
Polythene Tube ◽  
Healing Wound ◽  
Muscle Water

1. A skin lesion was made in rats by dorsal incision and the insertion of a polythene tube. 2. Over a period of 25 days after wounding, assays were performed for ascorbic acid, DNA, hydroxyproline, methionine, tryptophan, tyrosine and free amino acids in the lesion tissue. 3. The neutral-salt-soluble proteins of the lesion tissue were fractionated on DEAE-Sephadex, with the separation of fibrinogen and gamma-globulin from a serum protein fraction. 4. Over a period of 20 days after wounding, in wounded rats and in controls, assays were conducted for: ascorbic acid in lens and liver, hydroxyproline, soluble protein, methionine and water in muscle and tendon, and free amino acids in muscle. 5. Relative to controls there was a decrease in lens and liver ascorbic acid, a rise in tendon hydroxyproline, a rise in muscle free amino acids, a fall in muscle protein and a rise in tendon and muscle water.

scholarly journals Ingestion of Free Amino Acids as Opposed to Intact Protein Increases Amino Acid Absorption but Does Not Further Augment Postprandial Muscle Protein Synthesis Rates

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 673-673
Author(s):  
Michelle E G Weijzen ◽  
Rob JJ van Gassel ◽  
Imre W K Kouw ◽  
Stefan H M Gorissen ◽  
Marcel CG van de Poll ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Protein Digestion ◽  
Acid Absorption ◽  
Amino Acid Absorption

Abstract Objectives The rate of protein digestion and amino acid absorption determines the postprandial rise in circulating amino acids and, as such, modulates postprandial muscle protein synthesis rates. This study compares protein digestion and amino acid absorption kinetics and the subsequent muscle protein synthetic response following ingestion of intact protein versus an equivalent amount of free, crystalline amino acids. Methods Twenty-four healthy, young subjects (age: 22 ± 3 y, BMI: 23 ± 2 kg·m−2, sex: 12 M/12F) ingested 30 g intrinsically L-[1–13C]-phenylalanine and L-[1–13C]-leucine labeled milk protein (PROT; n = 12) or an equivalent amount of free amino acids (AA; n = 12). In addition, subjects received primed continuous L-[ring-2H5]-phenylalanine, L-[ring-3,5–2H2]-tyrosine, and L-[1–13C]-leucine infusions. Blood samples and muscle biopsies were obtained frequently to assess protein digestion and amino acid absorption kinetics and subsequent muscle protein synthesis rates over a 6 h postprandial period. An unpaired t-test was used to compare overall exogenous phenylalanine release in plasma. For other parameters repeated measures ANOVA were applied to determine differences between groups over time (time as within, and group as between-subjects factor). Data are expressed as mean ± SD. Results Postprandial plasma amino acid concentrations and exogenous phenylalanine appearance rates increased after ingestion of PROT and AA (both, P < 0.001), with a greater increase following ingestion of AA when compared to PROT (time*group interaction P < 0.001). Exogenous phenylalanine release in plasma assessed over the 6 h postprandial period, was greater in AA (76 ± 9%) compared with PROT (59 ± 10%; P < 0.001). Ingestion of AA and PROT strongly increased muscle protein synthesis rates based upon L-[ring-2H5]-phenylalanine (time effect P < 0.001), with no differences between groups (from 0.037 ± 0.015 to 0.053 ± 0.014%·h−1 and from 0.039 ± 0.016 to 0.051 ± 0.010%·h−1, respectively; time*group interaction P = 0.629). Conclusions Ingestion of free amino acids as opposed to intact milk protein is followed by more rapid amino acid absorption and greater postprandial plasma amino acid availability, but this does not further augment postprandial muscle protein synthesis rates. Funding Sources This research did not receive external funding.

scholarly journals Partial Characterization of a Low-Molecular-Mass Fraction with Cryoprotectant Activity from Jumbo Squid (Dosidicus gigas) Mantle Muscle

2019 ◽  
Vol 57 (1) ◽  
pp. 39-47
Author(s):  
Andrés Álvarez-Armenta ◽  
Ramón Pacheco-Aguilar ◽  
Juan Carlos Ramírez-Suárez ◽  
Susana María Scheuren-Acevedo ◽  
Enrique Márquez-Ríos ◽  
...  
Keyword(s):  
Amino Acids ◽  
Molecular Mass ◽  
Ammonium Chloride ◽  
Free Amino Acids ◽  
Free Amino ◽  
Mass Fraction ◽  
Muscle Protein ◽  
Protein Functionality ◽  
Dosidicus Gigas ◽  
Jumbo Squid

Freezing conditions affect fish muscle protein functionality due to its denaturation/aggregation. However, jumbo squid (Dosidicus gigas) muscle protein functionality remains stable even after freezing, probably due to the presence of low-molecular-mass compounds (LMMC) as cryoprotectants. Thus, water-soluble LMMC (<1 kDa) fraction obtained from jumbo squid muscle was evaluated by Fourier transform infrared spectrometry. From its spectra, total carbohydrates, free monosaccharides, free amino acids and ammonium chloride were determined. Cryoprotectant capacity and protein cryostability conferred by LMMC were investigated by differential scanning calorimetry. Fraction partial characterization showed that the main components are free amino acids (18.84 mg/g), carbohydrates (67.1 µg/mg) such as monosaccharides (51.1 µg/mg of glucose, fucose and arabinose in total) and ammonium chloride (220.4 µg/mg). Arginine, sarcosine and taurine were the main amino acids in the fraction. LMMC, at the mass fraction present in jumbo squid muscle, lowered the water freezing point to –1.2 °C, inhibiting recrystallization at 0.66 °C. Significant myofibrillar protein stabilization by LMMC was observed after a freeze-thaw cycle compared to control (muscle after extraction of LMMC), proving the effectiveness on jumbo squid protein muscle cryo- stability. Osmolytes in LMMC fraction inhibited protein denaturation/aggregation and ice recrystallization, maintaining the muscle structure stable under freezing conditions. LMMC conferred protein cryostability even at the very low mass fraction in the muscle.

scholarly journals Consequence of Free Amino Acids Generated from Decomposing Fish Muscle

1951 ◽  
Vol 16 (12) ◽  
pp. 10-16 ◽  
Author(s):  
Keishi AMANO ◽  
Masamichi BITO
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Fish Muscle

scholarly journals Measurement of the rates of protein synthesis in rabbits. A method for the estimation of rates of change in the specific radioactivities of free amino acids during continuous infusions

1980 ◽  
Vol 192 (2) ◽  
pp. 623-629 ◽  
Author(s):  
G E Lobley ◽  
S P Robins ◽  
R M Palmer ◽  
I McDonald
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Rate Constants ◽  
Free Amino Acids ◽  
Free Amino ◽  
Muscle Protein ◽  
Specific Radioactivity ◽  
Free Proline ◽  
Rates Of Change ◽  
New Zealand White Rabbits

1. A method is described by which, from analysis of terminal samples, the rate constants that define the changes in specific radioactivity of free amino acids during continuous infusions can be estimated. The method involves the infusion of 3H-labelled and 14C-labelled forms of an amino acid for different, but overlapping, periods. 2. The procedure was developed for infusions of proline and tyrosine into New Zealand White rabbits and the rate constants were determined for blood and muscle. 3. The rate constant for equilibrium of radioactive free proline was much lower in muscle than in blood, and indicated that a plateau condition may not be attained in muscle by the end of a 6 h infusion. 4. Comparison of the ratio of areas under the curves of estimated specific radioactivity plotted versus time with the 3H/14C ratio of bound amino acid in muscle protein suggested that radioactive proline and tyrosine may be incorporated preferentially from an extracellular rather than an intracellular source.

Response of tissues of the rat to anisosmolality in vivo

1993 ◽  
Vol 264 (6) ◽  
pp. R1164-R1179 ◽  
Author(s):  
J. J. Bedford ◽  
J. P. Leader
Keyword(s):  
Amino Acids ◽  
Sodium Chloride ◽  
Osmotic Stress ◽  
Free Amino Acids ◽  
Free Amino ◽  
Plasma Osmolality ◽  
Good Evidence ◽  
Daily Injection ◽  
Cardiac Ventricle

Rats were exposed to osmotic stress either acutely, over periods of 1 or 4 h, or chronically, over several days. In acute experiments, hyposmolality was induced by intraperitoneal infusion of dilute glucose or mannitol solutions, whereas hyperosmolality was induced by use of sodium chloride, concentrated glucose or mannitol solutions, or urea. Chronic hypernatremia was induced by daily administration of sodium chloride to water-deprived animals; chronic hyponatremia was induced by daily injection of antidiuretic hormone supplemented with glucose. Animals were made hyperglycemic using streptozotocin or uremic by ureteral ligation. Where appropriate, animals were anesthetized with thiobutabarbital (Inaktin) or ether. In acute experiments, analysis of the composition of the cardiac ventricle, diaphragm, liver, and renal cortex showed no evidence of cell volume regulatory processes involving transmembrane movement of potassium ions. There was a small but significant increase in free amino acids [measured as ninhydrin-positive substance (NPS)] in cardiac muscle exposed to hypertonic solutions of sodium chloride and glucose but not when plasma osmolality was raised using mannitol. In cerebral cortical tissue, after 4 h of exposure to acute hypertonicity by infusion of sodium chloride or glucose, there was a significant increase in tissue potassium content and a slight increase in NPS content. In chronic experiments, tissue analysis revealed good evidence for cellular volume readjustment only in cerebral cortex and heart. In the cortex, levels of free amino acids, principally taurine and glutamate (plus glutamine), showed large increases during hypernatremia and hyperglycemia and corresponding decreases during hyposmolality. In heart the principal amino acid present was taurine, and it, together with aspartate and glutamate (plus glutamine), showed large changes under osmotic stress. Other tissues analyzed showed only small changes in composition.

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