scholarly journals The fate of amino acids in isolated perfused livers of developing sheep

1979 ◽  
Vol 42 (3) ◽  
pp. 467-476 ◽  
Author(s):  
P. M. J. Savan ◽  
Majorie K. Jeacock ◽  
D. A. L. Shepherd

1. In order to establish whether or not there is a change in the relative rates of anabolism and catabolism of amino acids in the livers of lambs as they mature, a study has been made in isolated perfused livers obtained from foetal, suckling and ruminating lambs. The livers were perfused in a recirculating system and a mixture of amino acids (casein hydrolysate) was infused as substrate in the presence and absence of glucagon.2. The oxygen consumption of the livers per unit weight increased as the lambs matured but the uptake of α-amino nitrogen declined. A comparison of the rates of O2 consumption and substrate uptake indicated that in foetal lambs less than 20% of the amino acids could have been oxidized, whereas in ruminating lambs all the amino acids taken up could have been oxidized.3. In livers obtained from foetal lambs, the rate of urea production per unit weight of liver was approximately double that observed in ruminating lambs. Comparison of the rate of urea production and α-NH2-N uptake indicated that more than 60% of the substrate uptake was used for non-catabolic processes in the foetal lambs, whereas in ruminating animals all the α-NH2-N taken up could be accounted for as urea.4. Gluconeogenesis could not be detected in lambs at any age studied and glucagon had no effect on any of the parameters studied.

Parasitology ◽  
1958 ◽  
Vol 48 (1-2) ◽  
pp. 149-164 ◽  
Author(s):  
June P. Thurston

1. Standard conditions are described for preparing suspensions of washed Trypanosoma lewisi and T. equiperdum in modified Ringer–phosphate solution.2. Oxygen consumption was measured with differential manometers, using microflasks containing 2–5 × 107 trypanosomes in 0·9 ml. of reaction mixture. Measurements of oxygen uptake were carried out at 37° C.3. T. lewisi respired slowly in the absence of substrate for up to 2 hr. The trypanosomes suffered little damage when stored at 5° C. for 24 hr. without substrate. No oxygen uptake was observed with T. equiperdum in the absence of substrate. The trypanosomes were viable after 24 hr. at 5° C. with glucose or glycerol as substrate, but not in the absence of substrate.4. With glucose as substrate, the rate of oxygen consumption by T. lewisi increased with the age of infection. This change was more marked with glutamine as substrate.5. With glucosamine as substrate, the oxygen uptake of T. lewisi was at a slightly lower rate than with glucose. The rate of oxygen uptake was still lower with Na l-glutamic acid, asparagine, aspartic acid, casein hydrolysate, yeast extract and Difco Bacto-peptone. Thirteen other amino-acids had no effect on the motility of the trypanosomes.6. With glycerol as substrate, the oxygen uptake of T. equiperdum was at a slightly lower rate than with glucose. The rate of oxygen uptake was very low with yeast extract, casein hydrolysate and Difco Bacto-peptone. No oxygen uptake or motility was recorded with glutamine, Na l-glutamic acid, glucosamine, asparagine, aspartic acid, dl-alanine, or Na acetate. Thirteen other amino-acids had no effect on the motility of the trypanosomes.7. Ammonia was liberated from glutamine by adult and reproductive phase T. lewisi.


1938 ◽  
Vol 28 (1) ◽  
pp. 135-173 ◽  
Author(s):  
F. W. Foreman

1. Studies lead to the conclusion that Chibnall-preparations of pasturage proteins, in spite of their small amounts of carbohydrate impurity, may yet yield, on hydrolysis by mineral acids, practically the right amounts even of most of those amino-acids which are adversely affected by carbohydrates to some extent when tested singly under the conditions.2. Preparations made in another way after treating the pasturage with ether as in the original Chibnall-method showed features of interest in the problem of attaining very pure proteins now much needed for purposes of comparison.3. A new method is introduced by which it is possible to compare what may be extracted from the protoplasm of fresh unpulverized pasturages with the composition of the natural saps on a unit weight basis.4. Production and breakdown of protoplasmic protein in perennial rye-grass during growth consistently appeared related to variations in the content of “nitrogen” and phosphates in the saps and the supplies of “nitrogen” and phosphates from the soil.


1985 ◽  
Vol 63 (5) ◽  
pp. 881-884 ◽  
Author(s):  
Trung Chanh Ta ◽  
Kenneth W. Joy

The fate of 15N from the amino group of labelled asparagine was followed in growing pea leaves, in the presence and absence of inhibitors of deamidation (DONV, 5-diazo-4-oxo-L-norvaline) and transamination (AOA, aminooxyacetate). The label was widely incorporated into various amino acids, especially aspartate, glutamate, alanine, and homoserine, as well as glycine and serine. Treatment with AOA considerably decreased the label of all these amino acids except aspartate, consistent with the production of the latter by deamidation of asparagine. This was confirmed by the use of DONV, which decreased aspartate labelling by over 70%; a similar decrease in glutamate labelling suggested that the latter was labelled predominantly by transamination of aspartate. In contrast, DONV had a much smaller effect on the labelling of alanine, homoserine, glycine, and serine, indicating a direct transfer of amino nitrogen from asparagine, rather than transfer from aspartate (or glutamate). The labelling of glycine and serine and the transfer of amino nitrogen to ammonia and glutamine (amide group) were consistent with a flow of asparagine nitrogen into the photorespiratory nitrogen cycle. During leaf expansion there was a decrease in the amount of asparagine metabolised, and a decreasing participation of deamidation as the leaf matured.


1981 ◽  
Vol 241 (6) ◽  
pp. E415-E419 ◽  
Author(s):  
W. E. Mitch

Hepatic urea production is increased in acutely uremic rats, but it is not known whether this is related to release of nitrogen from nonhepatic tissues. Rats with acute uremia had lower arterial concentrations of alanine, glutamine, and alpha-amino nitrogen when compared to sham-operated rats and released significantly more alpha-amino nitrogen from the hindquarter in situ. Release of alpha-amino nitrogen, alanine, and glutamine from the perfused hindquarter of acutely uremic rats was greater than that of sham-operated rats. These changes in situ and in the perfused hindquarter were more pronounced in rats deprived of food and water compared to fed animals and were not due to depletion of intracellular amino acids. In addition to increased amino acid nitrogen release, there was a higher urea appearance rate (excretion plus accumulation) in starved, uremic rats compared to sham-operated controls (244.7 +/- 11.2 vs. 182.0 +/- 12.4 mg. 100 g-1 .48 h-1); urea appearance also was suppressed partially by feeding. Both peripheral release of amino acids and diet influence waste nitrogen production in acute uremia.


1975 ◽  
Vol 33 (1) ◽  
pp. 95-100 ◽  
Author(s):  
D. B. A. Silk ◽  
M. L. Clark ◽  
T. C. Marrs ◽  
Jill M. Addison ◽  
D. Burston ◽  
...  

1. An intestinal perfusion technique was used in six normal human subjects to study absorption of sixteen individual amino acids from an amino acid mixture simulating casein and from an enzymic hydrolysate of casein, prepared for oral administration to these subjects, which consisted of a mixture of oligopeptides and free amino acids.2. Total absorption of α-amino nitrogen was greater from the casein hydrolysate than from the amino acid mixture, and the considerable variation in percentage absorption of individual amino acids from the amino acid mixture was much reduced when the enzymic hydrolysate solution was perfused, as a number of amino acids which were poorly absorbed from the amino acid mixture were absorbed to a greater extent from the casein hydrolysate.3. These findings indicate that after extensive intestinal resections or in malabsorption there might be significant nutritional advantages in the administration of protein hydrolysates rather than amino acid mixtures.


2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Rahmawati Rahmawati ◽  
Trimayasari Trimayasari ◽  
Ghozali Akhmad Mustaqim ◽  
Wening Dwi Prastiwi ◽  
Emas Agus Prastyo Wibowo

AbstractSoap facial cleanser is needed to keep the facial skin to keep them clean and healthy. The purpose of this study to make soap cleanser with natural materials such as hard water deposits leri. This is because the use of leri water starch or starch granules of fine particles contained in water leri dansel dust can shed the dead skin on the face because of the essential amino acids contained can regenerate skin cells. In addition, water leri can brighten the face because the leri water oryzanol contain substances that can update the development and formation of the pigment melanin, which is effectively to ward off ultraviolet rays. The process of making soap using the principle of saponification reaction, namely the reaction between the oil and the KOH/NaOH. Facial cleansing soap made in this study is solid soap. Based on the results of quality test, soap solid leri water has a pH of 11.1, saponification number is 33, the water content of 46% as well as respondents to the test aspects of aroma and foam shows good results so this water leri treatment can be an alternative solution to prevent the use of soap facial cleansers that contain harmful chemicals. Keywords: air leri, soap cleanser, saponification  AbstrakSabun pembersih wajah sangat diperlukan untuk menjaga kulit wajah agar tetap bersih dan sehat. Tujuan dari penelitian ini untuk membuat sabun pembersih wajah dengan bahan alami berupa endapan air leri. Penggunaan air leri ini dikarenakan butiran partikel starch atau pati halus yang terdapat dalam air leri dapat merontokkan debu dansel kulit mati pada wajah karena asam amino esensial yang terkandung dapat meregenerasi sel-sel kulit. Selain itu, air leri dapat mencerahkan wajah karena air leri mengandung zat oryzanol yang dapat memperbarui perkembangan dan pembentukan pigmen melanin, yang efektif guna menangkal sinar ultraviolet. Proses pembuatan sabun menggunakan prinsip reaksi saponifikasi, yaitu reaksi antara minyak dan KOH/NaOH. Sabun pembersih wajah yang dibuat dalam penelitian ini ialah sabun padat. Berdasarkan hasil uji mutu, sabun air leri padat memiliki pH 11,1, angka penyabunan sebesar 33 kadar air 46 kadar air 46 % serta uji responden terhadap aspek aroma dan busa yang menunjukkan hasil cukup baik sehingga pengolahan air leri ini dapat menjadi solusi alternative untuk mencegah penggunaan sabun pembersih wajah yang mengandung bahan kimia berbahaya. Kata kunci: air leri, sabun pembersih wajah, saponifikasi 


1972 ◽  
Vol 50 (4) ◽  
pp. 803-818 ◽  
Author(s):  
Hans E. Gruen ◽  
Sheue-heng Wu

Isolated Flammulina velutipes fruit bodies were cultured under sterile conditions with the cut base immersed in water or solutions. Stipe elongation on water was only 6% of normal for fruit bodies isolated at 1.1–2.0 cm length, 19% at 5.1–6.0 cm, and the same as for fruit bodies attached to mycelium at 9.1–10.0 cm. Fruit bodies not immersed in water grew less in a saturated atmosphere than those in water. The mycelium must supply other substances than water for normal elongation during about two-thirds of the growth period, and only water thereafter. Isolated fruit bodies fed with filtered glucose, trehalose, sucrose, or mannitol grew better than on water. Maltose and fructose increased elongation only slightly, and sorbose had no effect. Potato extract, yeast extract, and casein hydrolysate gave no or very little growth promotion, but addition of glucose strongly increased growth on the natural extracts compared to glucose alone. Of 21 amino acids added separately to glucose, only asparagine, hydroxyproline, arginine, and to a lesser extent glutamine, stimulated growth of isolated fruit bodies. Growth was not promoted by pure asparagine, glutamine, and serine, or by thiamin or indoleacetic acid. Growth was inhibited by urea, ammonium nitrate, and ammonium tartrate with or without glucose.Growth promoting substances were most effective in young fruit bodies and except for glucose the promotion disappeared in fruit bodies isolated at 6.1–7.0 cm length, which corresponds to the end of the period of rapid elongation. Apical portions of fruit bodies with caps grew better on glucose than whole fruit bodies. Growth of decapitated isolated stipes was not promoted by nutrients.


2020 ◽  
pp. 1-9
Author(s):  
Keum-Ah Lee ◽  
Youngnam Kim ◽  
Hossein Alizadeh ◽  
David W.M. Leung

Abstract Seed priming with water (hydropriming or HP) has been shown to be beneficial for seed germination and plant growth. However, there is little information on the effects of seed priming with amino acids and casein hydrolysate (CH) compared with HP, particularly in relation to early post-germinative seedling growth under salinity stress. In this study, Italian ryegrass seeds (Lolium multiflorum L.) were primed with 1 mM of each of the 20 protein amino acids and CH (200 mg l−1) before they were germinated in 0, 60 and 90 mM NaCl in Petri dishes for 4 d in darkness. Germination percentage (GP), radicle length (RL) and peroxidase (POD) activity in the root of 4-d-old Italian ryegrass seedlings were investigated. Generally, when the seeds were germinated in 0, 60 and 90 mM NaCl, there was no significant difference in GP of seeds among various priming treatments, except that a higher GP was observed in seeds of HP treatment compared with the non-primed seeds when incubated in 60 mM NaCl. When incubated in 60 and 90 mM NaCl, seedlings from seeds primed with L-methionine or CH exhibited greater RL (greater protection against salinity stress) and higher root POD activity than those from non-primed and hydro-primed seeds. Under salinity stress, there were higher levels of malondialdehyde (MDA) in the root of 4-d-old Italian ryegrass seedlings, a marker of oxidative stress, but seed priming with CH was effective in reducing the salinity-triggered increase in MDA content. These results suggest that priming with L-methionine or CH would be better than HP for the protection of seedling root growth under salinity stress and might be associated with enhanced antioxidative defence against salinity-induced oxidative stress.


1944 ◽  
Vol 79 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Frank L. Engel ◽  
Helen C. Harrison ◽  
C. N. H. Long

1. In a series of rats subjected to hemorrhage and shock a high negative correlation was found between the portal and peripheral venous oxygen saturations and the arterial blood pressure on the one hand, and the blood amino nitrogen levels on the other, and a high positive correlation between the portal and the peripheral oxygen saturations and between each of these and the blood pressure. 2. In five cats subjected to hemorrhage and shock the rise in plasma amino nitrogen and the fall in peripheral and portal venous oxygen saturations were confirmed. Further it was shown that the hepatic vein oxygen saturation falls early in shock while the arterial oxygen saturation showed no alteration except terminally, when it may fall also. 3. Ligation of the hepatic artery in rats did not affect the liver's ability to deaminate amino acids. Hemorrhage in a series of hepatic artery ligated rats did not produce any greater rise in the blood amino nitrogen than a similar hemorrhage in normal rats. The hepatic artery probably cannot compensate to any degree for the decrease in portal blood flow in shock. 4. An operation was devised whereby the viscera and portal circulation of the rat were eliminated and the liver maintained only on its arterial circulation. The ability of such a liver to metabolize amino acids was found to be less than either the normal or the hepatic artery ligated liver and to have very little reserve. 5. On complete occlusion of the circulation to the rat liver this organ was found to resist anoxia up to 45 minutes. With further anoxia irreversible damage to this organ's ability to handle amino acids occurred. 6. It is concluded that the blood amino nitrogen rise during shock results from an increased breakdown of protein in the peripheral tissues, the products of which accumulate either because they do not circulate through the liver at a sufficiently rapid rate or because with continued anoxia intrinsic damage may occur to the hepatic parenchyma so that it cannot dispose of amino acids.


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