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.

scholarly journals Amino acid regulation of synthesis of ribonucleic acid and protein in the liver of rats

1971 ◽  
Vol 124 (2) ◽  
pp. 385-392 ◽  
Author(s):  
R. W. Wannemacher ◽  
C. F. Wannemacher ◽  
M. B. Yatvin
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Free Amino Acids ◽  
Free Amino ◽  
Cellular Protein ◽  
Deficient Diet ◽  
Cellular Protein Content ◽  
Regulate Protein

Weanling (23-day-old) rats were fed on either a low-protein diet (6% casein) or a diet containing an adequate amount of protein (18% casein) for 28 days. Hepatic cells from animals fed on the deficient diet were characterized by markedly lower concentrations of protein and RNA in all cellular fractions as compared with cells from control rats. The bound rRNA fraction was decreased to the greatest degree, whereas the free ribosomal concentrations were only slightly less than in control animals. A good correlation was observed between the rate of hepatic protein synthesis in vivo and the cellular protein content of the liver. Rates of protein synthesis both in vivo and in vitro were directly correlated with the hepatic concentration of individual free amino acids that are essential for protein synthesis. The decreased protein-synthetic ability of the ribosomes from the liver of protein-deprived rats was related to a decrease in the number of active ribosomes and heavy polyribosomes. The lower ribosomal content of the hepatocytes was correlated with the decreased concentration of essential free amino acids. In the protein-deprived rats, the rate of accumulation of newly synthesized cytoplasmic rRNA was markedly decreased compared with control animals. From these results it was concluded that amino acids regulate protein synthesis (1) by affecting the number of ribosomes that actively synthesize protein and (2) by inhibiting the rate of synthesis of new ribosomes. Both of these processes may involve the synthesis of proteins with a rapid rate of turnover.

Correlation between osmoregulation and cell volume regulation

1987 ◽  
Vol 252 (4) ◽  
pp. R768-R773
Author(s):  
M. A. Lang
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Osmotic Pressure ◽  
Cell Volume ◽  
Free Amino Acids ◽  
Volume Regulation ◽  
Free Amino ◽  
Cell Volume Regulation

The euryhaline crab, Callinectes sapidus, behaves both as an osmoregulator when equilibrated in salines in the range of 800 mosM and below and an osmoconformer when equilibrated in salines above 800 mosM. There exists a close correlation between osmoregulation seen in the whole animal in vivo and cell volume regulation studied in vitro. Hyperregulation of the hemolymph osmotic pressure and cell volume regulation both occurred in salines at approximately 800 mosM and below. During long-term equilibration of the crabs to a wide range of saline environments, the total concentration of hemolymph amino acids plus taurine remained below 3 mM. During the first 6 h after an acute osmotic stress to the whole animal, the hemolymph osmotic pressure and Na activity gradually decreased, whereas the free amino acids remained below 3 mM. As the hemolymph osmotic pressure decreased below approximately 850 mosM, the amino acid level began to increase to 17-25 mM. This change was primarily due to increases in glycine, proline, taurine, and alanine. The likely source of the increase in hemolymph free amino acids in vivo is the free amino acid loss from muscle cells observed during cell volume regulation in vitro.

scholarly journals THE CHEMISTRY OF INSECT HEMOLYMPH

1956 ◽  
Vol 39 (6) ◽  
pp. 853-868 ◽  
Author(s):  
G. R. Wyatt ◽  
T. C. Loughheed ◽  
S. S. Wyatt
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Developmental Stages ◽  
Galleria Mellonella ◽  
Similar Distribution ◽  
Total Acid ◽  
Protein Nitrogen ◽  
Larval Hemolymph

1. Hemolymph was collected for analysis from the silkworm, Bombyx mori, in a series of developmental stages ranging from the second molt to the late pupa. The mean pH of larval hemolymph after collection was found to be 6.45, that of pupal hemolymph, 6.57; in vivo values may be slightly lower. Total dry solids ranged from 5.4 to 10.6 per cent. Total protein ranged from 1.2 to 5.3 per cent, increasing rapidly during the fifth instar. 2. Free amino acids were separated chromatographically and estimated. Of 19 amino acids identified, amounting collectively to 823 to 1497 mg. per 100 ml., glutamine, histidine, and lysine generally occurred in greatest amount. Tryptophan was not detected, and cystine (or cysteine) was found in only one sample. The total free amino acids account for 35 to 55 per cent of the non-protein nitrogen of the plasma. 3. Free sugars, estimated semiquantitatively on chromatograms, comprise glucose, fructose, and sucrose in total amount ranging from about 5 to 40 mg. per 100 ml. Total acid-soluble, ultrafiltrable carbohydrate, estimated as glucose by the anthrone reaction, ranged from 166 to 635 mg. per 100 ml., indicating the presence of low molecular weight sugar derivatives. 4. Inorganic phosphate amounted to 5 to 15 mg. per 100 ml., and acid-soluble organic phosphate to 100 to 200 mg. per 100 ml. The latter fraction includes several substances, of which one was tentatively identified as glucose-6-phosphate and the remainder are as yet unidentified. 5. Single samples of hemolymph were also taken from larvae of the wax moth, Galleria mellonella, and the spruce sawfly, Diprion hercyniae. These contained even higher concentrations of solutes than the silkworm samples, but with a generally similar distribution. The proportions of the free amino acids were different in each species.

scholarly journals Compartmentation of albumin and ferritin synthesis in rat liver in vivo

1976 ◽  
Vol 156 (1) ◽  
pp. 189-192 ◽  
Author(s):  
E B Fern ◽  
P J Garlick
Keyword(s):  
Amino Acids ◽  
Rat Liver ◽  
Free Amino Acids ◽  
Free Amino ◽  
Plasma Albumin ◽  
Ferritin Synthesis ◽  
Liver Ferritin ◽  
Ferritin Synthesis In

Infusion of rats with [U-14C]glycine resulted in labelling of glycine and serine in plasma albumin and liver ferritin. The patterms of labelling in these two proteins were not similar, suggesting that each is synthesized from a different pool of free amino acids.

Free amino acids of Nicotiana alata anthers during development in vivo

1983 ◽  
Vol 57 (4) ◽  
pp. 527-531 ◽  
Author(s):  
Helle Krogaard ◽  
A. Skytt Andersen
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Nicotiana Alata

scholarly journals Free amino acids of testes. Concentrations of free amino acids in the testes of several species and the precursors of glutamate and glutamine in rat testes in vivo

1973 ◽  
Vol 132 (3) ◽  
pp. 353-359 ◽  
Author(s):  
Isa K. Mushahwar ◽  
Roger E. Koeppe
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Guinea Pig ◽  
Free Amino Acids ◽  
Free Amino ◽  
Ammonium Acetate ◽  
Testicular Tissue ◽  
Species Variation

Determination of the free amino acid and lactate content of testicular tissue in rat, guinea pig, rabbit, cat, gerbil, hamster, chicken and bullfrog indicates a substantial species variation. Insulin hypoglycaemia and ammonium acetate toxicity changes the concentration of several free amino acids of rat testes. 14C radioactivity from labelled acetate and ethanol is rapidly incorporated into some of the free amino acids of rat testes in vivo, whereas incorporation from [14C]glucose is relatively slow. These results have been compared with those obtained from similar studies with rat brain. In contrast to brain, there is no evidence for glutamate compartmentation in testes.

In vivo oocyte hydration in Atlantic halibut (Hippoglossus hippoglossus); proteolytic liberation of free amino acids, and ion transport, are driving forces for osmotic water influx

2002 ◽  
Vol 205 (2) ◽  
pp. 211-224
Author(s):  
Roderick Nigel Finn ◽  
Gunn C. Østby ◽  
Birgitta Norberg ◽  
Hans Jørgen Fyhn
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Driving Forces ◽  
Atlantic Halibut ◽  
Hippoglossus Hippoglossus ◽  
Oocyte Hydration ◽  
Osmotic Water ◽  
Cellular Water

SUMMARY The in vivo swelling and hydration of maturing oocytes of Atlantic halibut Hippoglossus hippoglossus were studied in order to characterise the osmotic mechanism underlying oocyte hydration in oviparous marine teleosts that spawn pelagic eggs. Sequential biopsies from two females, spanning four hydration cycles, were examined by osmometry, solute analysis and electrophoresis of dissected hydrating oocytes and ovulated eggs. The hydration cycle of the biopsied halibuts lasted 33–54 h. The majority of ovarian oocytes existed in a pre-hydrated condition (individual wet mass approx. 3.7 mg, diameter approx. 1.87 mm, 63 % H2O) with easily visible, non-coalesced, yolk platelets. Group-synchronous batches of the pre-hydrated oocytes increased in individual wet mass, diameter and water content to reach the ovulated egg stage of approximately 15 mg, 3.0 mm and 90 % H2O, respectively. The yolk osmolality of the hydrating oocytes was transiently hyperosmotic to the ovarian fluid (range 305–350 mOsmol l–1) with a peak osmolality of about 450 mOsmol l–1 in oocytes of 6–8 mg individual wet mass. The transient hyperosmolality was well accounted for by the increase in oocyte content of free amino acids (FAAs; approx. 2300 nmol oocyte–1), K+ (approx. 750 nmol oocyte–1), Cl– (approx. 900 nmol oocyte–1), total ammonium (approx. 300 nmol oocyte–1) and inorganic phosphate (Pi; approx. 200 nmol oocyte–1) when relating to the increase in cellular water. The oocyte content of Na+ did not increase during the hydration phase. Extensive proteolysis of yolk proteins, in particular a 110 kDa protein, correlated with the increase in the FAA pool, although the latter increased by approx. 20 % more than could be accounted for by the decrease in the oocyte protein content. Both indispensable and dispensable amino acids increased in the FAA pool, and particularly serine, alanine, leucine, lysine, glutamine and glutamate. Taurine content remained stable at approx. 70 nmol oocyte–1 during oocyte hydration. The results show that final hydration of Atlantic halibut oocytes is caused by an osmotic water uptake in which FAAs, derived mainly from the hydrolysis of a 110 kDa yolk protein, contribute approximately 50 % of the yolk osmolality and ions (Cl–, K+, Pi, NH4+) make up the balance.

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.

INCORPORATION OF14C FROM [U-14C]GLUCOSE INTO FREE AMINO ACIDS IN MOUSE BRAIN LOCI IN VIVO UNDER NORMAL CONDITIONS

1973 ◽  
Vol 20 (5) ◽  
pp. 1337-1344 ◽  
Author(s):  
M. Shimada ◽  
T. Kihara ◽  
K. Kurimoto ◽  
M. Watanabe
Keyword(s):  
Amino Acids ◽  
Mouse Brain ◽  
Free Amino Acids ◽  
Free Amino
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