scholarly journals A procedure for the quantitative analysis of the sulphur amino acids of rat tissues

1967 ◽  
Vol 102 (3) ◽  
pp. 959-975 ◽  
Author(s):  
M. K. Gaitonde ◽  
G. E. Gaull
Keyword(s):  
Amino Acids ◽  
Rat Liver ◽  
Rat Tissues ◽  
Sulphur Compounds ◽  
One Dimensional ◽  
Quantitative Separation ◽  
Exchange Resins ◽  
Sulphur Amino Acids ◽  
Dowex 1

1. A method is described for the quantitative separation of the sulphur compounds in a single sample of tissue by passing an extract through a serial assembly of ion-exchange resins in the order: Dowex 2 (Cl(-) form), Dowex 1 (CO(3) (2-) form), Amberlite CG-50 (H(+) form) and Zeo-Karb 225 (H(+) form). 2. Groups of sulphur amino acids were eluted separately from each column; the recovery of sulphur compounds after their labelling with (35)S in vivo by injection of l-[(35)S]-methionine was 91-106%. Individual sulphur compounds were further resolved by one-dimensional or two-dimensional paper chromatography. 3. Evidence is presented on the occurrence of S-adenosylmethionine and S-adenosylhomocysteine in rat liver and brain. Rat liver and brain contained 83.6 and 31.4mmu-moles/g. respectively of S-adenosylmethionine.

scholarly journals Effects of the hepatotoxic agents retrorsine and aflatoxin B1 on hepatic protein synthesis in the rat

1968 ◽  
Vol 109 (1) ◽  
pp. 87-91 ◽  
Author(s):  
S. Villa-Treviño ◽  
D. D. Leaver
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Rat Liver ◽  
Aflatoxin B1 ◽  
Plasma Proteins ◽  
Pyrrolizidine Alkaloid ◽  
Main Site ◽  
Nuclear Rna ◽  
Hepatic Protein Synthesis

1. Aflatoxin and the pyrrolizidine alkaloid retrorsine inhibited the incorporation of labelled amino acids into rat liver and plasma proteins in vivo. Inhibition was greater and detected earlier with retrorsine (1hr.) than with aflatoxin (3hr.). 2. Both toxins affected the liver ribosomal aggregates, causing increases in the proportion of monomers plus dimers. The effect of retrorsine was greater than that of aflatoxin. 3. Incorporation of labelled amino acids into proteins of cell-free preparations of liver from rats treated with aflatoxin was lower than in control preparations. The main site of inhibition appeared to be the ribosomes. 4. Both toxins inhibited the incorporation of orotate into liver nuclear RNA 1hr. after administration.

scholarly journals Enzymic determination of branched-chain amino acids and 2-oxoacids in rat tissues. Transfer of 2-oxoacids from skeletal muscle to liver in vivo

1980 ◽  
Vol 188 (3) ◽  
pp. 705-713 ◽  
Author(s):  
G Livesey ◽  
P Lund
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Bacillus Subtilis ◽  
Branched Chain Amino Acids ◽  
Rat Tissues ◽  
Arterial Blood ◽  
Branched Chain ◽  
Arteriovenous Difference

1. A procedure is described for the purification of leucine dehydrogenase (EC 1.4.1.9) from Bacillus subtilis. 2. The preparation is suitable for the quantitative assay of branched-chain amino acids and their 2-oxoacid analogues. 3. The content of total branched-chain 2-oxoacids in freeze-clamped liver, kidney, heart or mammary gland of fed rats is less than 5 nmol/g fresh wt. Higher amounts are present in skeletal muscle and arterial blood (25 +/- 4 nmol per g fresh wt., and 33 +/- 6 nmol per ml respectively; means +/- S.D. of 3 and 11 animals respectively). The values are not significantly affected by starvation for 24 h. 4. Arteriovenous difference measurements show that considerable amounts of branched-chain 2-oxoacids are released by skeletal muscle into the circulation and similar amounts are removed by the liver (about 1 mmol/24 h in a 400 g rat).

scholarly journals Ontogenic changes in hepatic glutathione and metallothionein in rats and the effect of a low-sulphur-containing diet

1990 ◽  
Vol 63 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Misako Taniguchi ◽  
M. George Cherian
Keyword(s):  
Amino Acids ◽  
Rat Liver ◽  
Soya Bean ◽  
Protein Diet ◽  
Major Protein ◽  
Newborn Rat ◽  
Pregnant Rats ◽  
Hepatic Glutathione ◽  
Sulphur Amino Acids ◽  
Bean Protein

Metallothionein contains about 30% cysteine and is a major protein in newborn rat liver. This protein and glutathione constitute two major intracellular cysteine pools in newborn rat liver. When pregnant rats were fed on a soya-bean-protein diet, low in sulphur amino acids, the hepatic glutathione levels of the dams were decreased. However, this did not affect the levels of glutathione or metallothionein in the pups. The activity of the glutathione-degrading enzyme γ-glutamyltransferase (EC2.3.2.2) in the livers of pups was maximum at birth and gradually decreased with age when the hepatic glutathione was transported to the kidney. In the pups born from dams fed on soya-bean-protein diet the decline in the hepatic enzyme activity was delayed, suggesting a continued degradation of glutathione in the liver. These results suggest that even with a maternal nutritional deficiency of sulphur amino acids, the transfer of cysteine to the fetus is not impaired. However, the hepatic intra-organ degradation of glutathione is continued in these pups for a prolonged period after birth compared with pups born from control mothers. The increased degradation of glutathione in the liver may be essential to meet the requirement of cysteine in pups born from dams fed on the soya-bean-protein diet.

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.

EFFECT OF LITHIUM ON DEIODINATING ACTIVITY OF VARIOUS RAT TISSUES IN VITRO

1974 ◽  
Vol 76 (2) ◽  
pp. 260-272 ◽  
Author(s):  
P. T. Männistö
Keyword(s):  
Amino Acids ◽  
Lithium Chloride ◽  
Half Life ◽  
Rat Tissues ◽  
Biological Half Life ◽  
Liver And Kidney ◽  
Licl Treatment

ABSTRACT The effect of lithium chloride (LiCl) on the deiodination of iodotyrosines, on the degradation of 125I-L-thyroxine (125I-L-T4) in vitro and on the disappearance of exogenous 125I-L4 and 125I-rat-TSH in vivo was studied in rats. Iodotyrosine deiodination was studied in vitro with three techniques. The whole thyroid lobes were not satisfactory as substrate. When a diluted mixture of prelabelled iodo-amino acids was used as substrate, thyroid homogenates deiodinated iodotyrosines. The reaction was inhibited by boiling and by 3,5-dinitro-L-tyrosine (DNT), but LiCl (2 × 10−2 m) had no effect. When 125I-3-iodo-L-tyrosine (125I-L-MIT) served as substrate, increasing concentrations of thyroid homogenates showed an increasing deicdinating activity, which was stimulated by NADP (1.5 × 10−4 m). Inhibitors of dehalogenase DNT (10−4 and 10 −3 m) and menandione (10−4 m) inhibited deiodination, but LiCl (5×10−3 − 0.1 m) was again without effect. The degradation of 125I-L-T4 by liver and kidney homogenates was inhibited by LiCl (5 × 10−3 − 0.1 m). The disappearance of 125I-L-T4 was studied in rats treated with LiCl for 1 – 4 or 60 – 64 days in vivo. The half-lives were as follows: at 1 –4 days, the control rats 15.9 ± 1.3 h and the LiCl treated rats 19.1 ± 2.1 h (P < 0.05) and at 60 – 64 days 11.2 ± 2.0 h and 66.8 ± 12.3 h (P < respectively. The prolonged half-life in the LiCl treated rats was not due to the decreased excretion of radioactivity in the urine or faeces. The biological half-life of 125I-rat-TSH (11.4 ± 3.2 min) was not modified by LiCl treatment for 5 days. It can be concluded that the antithyroid effect of LiCl neither originates from the inhibition of iodotyrosine deiodination nor from the change in the half-life of TSH. The half-life of thyroxine is prolonged by LiCl, an effect which is perhaps due to the decreased degradation of thyroxine by tissues.

scholarly journals Citrulline synthesis in rat tissues and liver content of carbamoyl phosphate and ornithine

1974 ◽  
Vol 138 (2) ◽  
pp. 225-232 ◽  
Author(s):  
Luisa Raijman
Keyword(s):  
Rat Liver ◽  
Soluble Fraction ◽  
Maximal Activity ◽  
Rat Tissues ◽  
Ornithine Carbamoyltransferase ◽  
Carbamoyl Phosphate Synthetase ◽  
Carbamoyl Phosphate ◽  
Citrulline Synthesis

Rat liver ornithine carbamoyltransferase appears to be located exclusively in the mitochondria; the activity that is found in the soluble fraction is indistinguishable from mitochondrial ornithine carbamoyltransferase by simple kinetic criteria, and seems to result from breakage of mitochondria during homogenization. Of several rat tissues studied, only the liver and the mucosa of small intestine contain significant amounts of ornithine carbamoyltransferase; the activity in intestinal mucosa is less than one thousandth of that in liver. Qualitatively, this distribution coincides with that of carbamoyl phosphate synthetase I and its cofactor, acetylglutamate. The rat liver contents of carbamoyl phosphate and ornithine were 0.1 and 0.15μmol/g wet wt. of tissue respectively. On the basis of these values, it is proposed that in vivo the ornithine carbamoyltransferase activity of liver may be much lower than its maximal activity in vitro might suggest.

scholarly journals Studies on cystathionase activity in rat liver and brain during development. Effects of hormones and amino acids in vivo

1973 ◽  
Vol 136 (4) ◽  
pp. 1011-1015 ◽  
Author(s):  
Kirsti Heinonen
Keyword(s):  
Amino Acids ◽  
Enzyme Activity ◽  
Rat Brain ◽  
High Activity ◽  
Rat Liver ◽  
Newborn Rats ◽  
Postnatal Rats

High activity of cystathionase was present in rat liver but only low amounts of activity in rat brain during development. Triamcinolone had no effect on liver cystathionase activity in foetuses but increased the enzyme activity significantly in postnatal rats. l-Thyroxine decreased liver cystathionase activity significantly in newborn rats; administration of pyridoxal 5′-phosphate did not prevent this effect. l-Methionine significantly increased liver cystathionase activity in newborn rats.

scholarly journals Metabolism of Sulphur Amino Acids I. the Uptake of Cysteine by Rat Liver

1957 ◽  
Vol 10 (2) ◽  
pp. 217 ◽  
Author(s):  
Eva Eden ◽  
Helen B Granowski ◽  
WG Jones ◽  
Judith A Linnane
Keyword(s):  
Amino Acids ◽  
Rat Liver ◽  
Normal Level ◽  
Intraperitoneal Injection ◽  
Stomach Tube ◽  
Sulphur Amino Acids

Cysteine was administered to rats by stomach tube. or by intraperitoneal injection. In some animals the concentration of glutathione in the liver was first lowered to 10 per cent. of the normal level by injecting the animals with bromobenzene. When 30mg of cysteine were given by stomach tube, 75 per cent. of the cysteine taken up by the liver in normal rats was oxidized in 1 hr to products other than cystine. In animals treated with bromo benzene all the cysteine was converted to glutathione and no increase could be found in the oxidized sulphur fraction. In both groups of animals only traces of cysteine were present.

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