Regulation of Cellular Osmolarity and Volume in Tetrahymena

1970 ◽  
Vol 53 (2) ◽  
pp. 391-399
Author(s):  
LARRY C. STONER ◽  
PHILIP B. DUNHAM
Keyword(s):  
Amino Acids ◽  
Osmotic Stress ◽  
Free Amino Acids ◽  
Free Amino ◽  
Freezing Point ◽  
Tetrahymena Pyriformis ◽  
Freezing Point Depression ◽  
Sodium Potassium ◽  
Cellular Volume ◽  
Intracellular Osmolarity

1. Tetrahymena pyriformis are hyperosmotic to external media of osmolarities from 2 to 171 m-osmole/l. The intracellular osmolarity, determined by freezing-point depression, is 111 m-osmole/kg cells in dilute media, and increases linearly with increasing external osmolarities. 2. Over 80% of the intracellular osmolarity can be attributed to the concentration of sodium, potassium, chloride and the free amino acids. 3. In response to an increase in the external osmolarity, Tetrahymena regulates its intracellular osmolarity by increasing the concentrations of free amino acids. 4. The regulation of cellular volume under conditions of osmotic stress is achieved by an increase in the amount of osmotically active solutes and the regulation of the rate of elimination of fluid by the contractile vacuole.

The effect of β-alanine on the concentration of taurine and other free amino acids during osmotic stress of Mytilus galloprovincialis

1987 ◽  
Vol 67 (1) ◽  
pp. 111-117 ◽  
Author(s):  
G. Sansone ◽  
M. Cotugno ◽  
I. Cosma ◽  
P. Zatta
Keyword(s):  
Amino Acids ◽  
Osmotic Stress ◽  
Free Amino Acids ◽  
Significant Variation ◽  
Free Amino ◽  
Mytilus Galloprovincialis ◽  
Cysteic Acid

The effect of β-alanine on the concentration of taurine and other free amino acids (FAA) in different osmotic conditions in Mytilus galloprovincialis have been investigated. Significant variation of the concentration of FAA as a function of the salinity have been observed.β-alanine incorporation decreases the level of cysteic acid and taurine as well as the level of other FAA.

scholarly journals CHANGES OF CONTENT OF FREE AMINO ACIDS IN GRAINS OF FOREST GROWING EASTERS OF EASTER TRANSBAIKALIA IN PULLING IN OSMOSITIC STRESS

2018 ◽  
pp. 83-89
Author(s):  
Евгений (Evgenij) Александрович (Аleksandrovich) Бондаревич (Bondarevich)
Keyword(s):  
Amino Acids ◽  
Osmotic Stress ◽  
Free Amino Acids ◽  
Free Amino ◽  
Agropyron Cristatum ◽  
Acidic Amino Acids ◽  
Subsequent Period ◽  
Stipa Krylovii ◽  
Wild Cereals ◽  
Biochemical Features

In the course of studying the content of free amino acids in dry and germinating grains of wild cereals, some biochemical features of their dynamics were revealed depending on the osmotic pressure. In most species, except Agropyron cristatum, a significant increase in the concentration of amino acids occurred in the control on the first day after the start of the experiment; in the subsequent period, their decrease was observed. For Agropyron cristatum, a decrease in the index and a smooth increase after the first day were observed. Under the influence of osmolyte, the tendency to mobilize amino acids has changed and in some species (Stipa krylovii, Melica virgata, Melica turczaninowiana) the maximum amounts were observed on the first day from the beginning of the experiment, in the others to the second day. The total amount of free amino acids in the control and in the test was not significantly different. There was also a rapid mobilization of proteinogenic amino acids with increasing osmotic stress for the widespread Stipa krylovii and Agropyron cristatum in the region. A similar trend was noted for the xerophyte Tripogon chinensis. For grasses with a narrow ecological niche, which are characterized by xeromesophilia, osmotic stress suppressed the rapid mobilization of free amino acids. The content of individual groups of amino acids under the influence of osmotic stress was characterized by significant differences for species of the Melica genus in the number of acidic amino acids, for Tripogon chinensis an increase in the content of basic amino acids, and for Agropyron cristatum by a decrease in their concentration.

The Composition of Haemolymth in Aquatic Insects

1962 ◽  
Vol 39 (3) ◽  
pp. 325-344 ◽  
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Amino Acids ◽  
Aquatic Insects ◽  
Free Amino Acids ◽  
Free Amino ◽  
Inorganic Phosphate ◽  
Potassium Concentration ◽  
Chloride Concentration ◽  
Sodium Concentration ◽  
Sodium Potassium ◽  
Sodium And Potassium

1. Analyses were made of haemolymph obtained from aquatic representatives of nine major orders in the Insecta. 2. In the Odonata, Plecoptera, Ephemeroptera and Hemiptera-Heteroptera, the sodium concentration is relatively high and the potassium concentration is low. The chloride concentration is relatively high, but it never exceeds the sodium concentration. 3. In the Neuroptera, Coleoptera, Trichoptera and Diptera the sodium concentration is relatively high and the potassium concentration is low. In Nymphula nymphaeta (Lepidoptera) both the sodium and potassium concentrations are low. In all of these endopterygotes the chloride concentration is relatively low. 4. There is no correlation between diet and the sodium/potassium ratio in haemolymph of aquatic insects. 5. The problem of cation-anion balance is discussed. It is suggested that free amino acids contribute little to the anion pool. Bicarbonate and phosphate, largely as inorganic phosphate, contribute a small amount to the anion pool in exopterygotes. Phosphate contributes considerably more to the anion pool in some endopterygotes. Nevertheless, in all of the insects investigated, there is a deficit of anions. This deficit is usually greater in the endopterygotes. 6. The calculated osmotic activities of the known ions and free amino acids are less than the observed osmotic activities of haemolymph. It is inferred that non-amino organic acids must be present. Preliminary investigations indicate that non-amino acids are present in the concentrations required to account for both the osmotic and the anion deficits.

scholarly journals The dynamics of free amino acids in the grains Tripogon chinensis (Franch.) Hack. when germinating in the conditions of the osmotic stress

2018 ◽  
Vol 11 ◽  
pp. 00033
Author(s):  
Irina Plyaskina ◽  
Evgenii Bondarevich ◽  
Igor Boriskin ◽  
Natalia Kotsyurzhinskaya ◽  
Ludmila Ishina
Keyword(s):  
Amino Acids ◽  
Osmotic Stress ◽  
Osmotic Pressure ◽  
Free Amino Acids ◽  
Free Amino ◽  
Basic Amino Acids ◽  
Protective Signaling ◽  
Hydrolysis Of ◽  
Arginine Concentration ◽  
Adaptive Reaction

The content of free amino acids in seeds and sprouts of T. chinensis in the control and at an osmotic pressure of 5 atm. was determined. The group of acidic and basic amino acids predominates in seeds. An adaptive reaction to a physiological drought is the transformation of the free amino acids metabolism. This is expressed in an increase in the total amount of free amino acids at the osmotic pressure of 5 atm., providing the osmotic component of adaptation. Under the conditions of the osmotic stress, the concentration of acidic and basic amino acids increases up to 48 hours, this may be due to the continued hydrolysis of reserve proteins. Under the influence of the osmotic stress there are changes in the group of amino acids, the metabolic precursor of which is glutamic acid. The amino acids, a part of this group, exhibit protective, signaling properties. Thus, the increase in the arginine concentration and ornithine is noted; this indicates the activation of the ornithine cycle and on the increase of amino acids catabolism. The revealed features can ensure the successful germination of T. chinensis grains under the conditions of the physiological drought.

The role of free amino acids in cellular osmoregulation in the freshwater bivalve Ligumia subrostrata (Say)

1976 ◽  
Vol 54 (11) ◽  
pp. 1927-1931 ◽  
Author(s):  
J. Alison Hanson ◽  
Thomas H. Dietz
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Pond Water ◽  
Freshwater Bivalve ◽  
Cellular Volume ◽  
Amino Acid Concentrations

Free amino acids constitute 11% of the cellular solute in Ligumia subrostrata acclimated in pond water but less than 1% of blood total solute. Arginine, glutamate, histidine, and alanine account for 60% of the cellular free amino acid concentration. Tissue free amino acid concentrations increase when the animals are exposed to dehydration and anoxic stress. Free amino acids contributing most to the elevated tissue amino acid concentrations are glutamate, alanine, threonine, and serine. These specific free amino acids play an important role in cellular volume regulation.

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.

Betaines and free amino acids in salt stressed vitroplants and winter resting buds of Populus trichocarpa x deltoides

1991 ◽  
Vol 83 (1) ◽  
pp. 136-143 ◽  
Author(s):  
L. Bray ◽  
D. Chriqui ◽  
K. Gloux ◽  
D. Le Rudulier ◽  
M. Meyer ◽  
...  
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Populus Trichocarpa
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