Factors affecting protein synthesis in rat kidney ribosome preparations

1970 ◽  
Vol 48 (1) ◽  
pp. 105-112 ◽  
Author(s):  
D. M. Nicholls ◽  
M. P. Ryan ◽  
S. H. Miall ◽  
I. D. Cappon
Keyword(s):  
Protein Synthesis ◽  
Rat Kidney ◽  
Insoluble Protein ◽  
Ribonuclease Inhibitor ◽  
Enzyme Preparations ◽  
Factors Affecting ◽  
Kidney Microsomes ◽  
Kidney Liver ◽  
Microsomal Pellet ◽  
Liver Ribosomes

Kidney ribosomes that were prepared from the postmitochondrial supernatant or the microsomal pellet of homogenates by deoxycholate treatment consisted mainly of monomers and dimers rather than polysomes. The addition of liver postmicrosomal supernatant to kidney homogenates or to kidney microsomes did not increase the polysome yield or the incorporation of 14C-leucine into hot acid-insoluble protein. In contrast to kidney, liver ribosomes that were prepared in the presence of liver supernatant (containing ribonuclease inhibitor) had an increased proportion of polysomes and an increased incorporation of 14C-leucine into protein compared to liver ribosomes prepared in the absence of supernatant.The incorporation of 14C-leucine into protein in kidney ribosome preparations was considerably lower than it was in liver ribosome preparations. The incorporation depended on the concentration of Mg2+, GTP, and pH 5 enzymes. Following preincubation of kidney ribosomes to eliminate endogenous mRNA, the incorporation of 14C-phenylalanine into peptide using either phenylalanine or phenylalanyl-tRNA was found to depend on the addition of poly U.Ribonuclease activity in kidney supernatant and pH 5 enzyme preparations was much greater than it was in liver preparations, and may partly account for the lower polysome yield and protein synthesis in kidney.

INHIBITION OF THYROGLOBULIN BIOSYNTHESIS AND DEGRADATION BY EXCESS IODIDE. SYNERGISM WITH LITHIUM

1976 ◽  
Vol 81 (2) ◽  
pp. 495-506 ◽  
Author(s):  
A. Radvila ◽  
R. Roost ◽  
H. Bürgi ◽  
H. Kohler ◽  
H. Studer
Keyword(s):  
Protein Synthesis ◽  
Thyroid Gland ◽  
Inhibitory Action ◽  
Inhibit Protein Synthesis ◽  
Thyrotrophic Hormone ◽  
Thyroid Glands ◽  
Pre Treatment ◽  
Excess Iodide ◽  
Kidney Liver

ABSTRACT Lithium and excess iodide inhibit the release of thyroid hormone from preformed stores. We thus tested the hypothesis that this was due to an inhibition of thyroglobulin breakdown. Rats were pre-treated with propylthiouracil (PTU) for 3 weeks in order to deplete their thyroids of thyroglobulin. While the PTU was continued, lithium chloride (0.25 mEq./100 g weight) or potassium iodide (3 mg per rat) were injected every 12 h for 3 days. Thereafter the thyroglobulin content in thyroid gland homogenates was measured. PTU pre-treatment lowered the thyroglobulin content from 4.21 to 0.22 mg/100 mg gland. Lithium caused a marked re-accumulation of thyroglobulin to 0.60 mg/100 mg within 3 days. While iodide alone had only a borderline effect, it markedly potentiated the action of lithium and a combination of the two drugs increased the thyroglobulin content to 1.04 mg/100 mg. Thyroxine was injected into similarly pre-treated animals to suppress secretion of thyrotrophic hormone. This markedly inhibited the proteolysis of thyroglobulin and 1.3 mg/100 mg gland accumulated after 3 days. Excess iodide, given in addition to thyroxine, decreased the amount of thyroglobulin accumulated to 0.75 mg/100 mg gland. To study whether this could be explained by an inhibitory action of iodide on thyroglobulin biosynthesis, thyroid glands from animals treated with excess iodide were incubated in vitro in the presence of 0.2 mm iodide for 3 h. Iodide decreased the incorporation of radioactive leucine into total thyroidal protein and into thyroglobulin by 25 and 35 % respectively. Iodide did not inhibit protein synthesis in the kidney, liver or muscle tissue. Thus, large doses of iodide selectively inhibit thyroglobulin biosynthesis.

Altered protein synthesis in rat kidney cells exposed to semiconductor materials

1994 ◽  
Vol 8 (3) ◽  
pp. 253-258 ◽  
Author(s):  
Yasunobu Aoki ◽  
Michael M. Lipsky ◽  
Bruce A. Fowler
Keyword(s):  
Protein Synthesis ◽  
Rat Kidney ◽  
Semiconductor Materials ◽  
Kidney Cells ◽  
Altered Protein

Use of an in Vitro Protein Synthesizing System to Test the Mode of Action of Chloracetamides

Weed Science ◽  
1980 ◽  
Vol 28 (3) ◽  
pp. 334-340 ◽  
Author(s):  
Luanne M. Deal ◽  
J. T. Reeves ◽  
B. A. Larkins ◽  
F. D. Hess
Keyword(s):  
Protein Synthesis ◽  
Sand Culture ◽  
Leucine Incorporation ◽  
Insoluble Protein ◽  
In Vitro System ◽  
A Cell ◽  
Protein Incorporation ◽  
Vitro Protein

The effects of chloracetamides on protein synthesis were studied both in vivo and in vitro. Four chloracetamide herbicides, alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide], metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], CDAA (N–N-diallyl-2-chloroacetamide), and propachlor (2-chloro-N-isopropylacetanilide) were tested for inhibition of [3H]-leucine incorporation into protein. Incorporation of3H-leucine into trichloroacetic acid (TCA)-insoluble protein was inhibited in oat (Avena sativaL. ‘Victory’) seedlings grown in sand culture and treated 12 h at 1 × 10−4M with these chloracetamides. The herbicides were also tested in a cell-free protein synthesizing system containing polyribosomes purified from oat root cytoplasm. These herbicides had no effect on the rates of polypeptide elongation nor on the synthesis of specific polypeptides when herbicides (1 × 10−4M) were added directly to the system. Polypeptide formation was inhibited 89% when 1 × 10−4M cycloheximide was added during translation. Cytoplasmic polyribosomes were isolated from oat roots treated 12 h with 1 × 10−4M herbicide. Translation rates and products were not altered when these polyribosomes were added to the in vitro system. Protein synthesis is inhibited when tested in an in vivo system; however, the inhibition does not occur during the translation of mRNA into protein.

scholarly journals Metabolism of parathyroid hormone. Degradation of 125I-labelled hormone by kidney enzyme

1969 ◽  
Vol 111 (4) ◽  
pp. 509-514 ◽  
Author(s):  
T. J. Martin ◽  
R. A. Melick ◽  
M. de Luise
Keyword(s):  
Parathyroid Hormone ◽  
Trichloroacetic Acid ◽  
Rat Kidney ◽  
Gel Filtration ◽  
Void Volume ◽  
Control Medium ◽  
Ph Values ◽  
Kidney Enzyme ◽  
Rapid Destruction ◽  
Kidney Microsomes

A study was made of the enzymic degradation of 125I-labelled parathyroid hormone by rat kidney microsomes. Incubation with microsomes resulted in rapid destruction of the labelled hormone. The microsomal factor was not separable by dialysis, and the reaction was favoured by pH values in the physiological range. Velocity of the reaction varied directly as the substrate concentration, and additional crude parathyroid hormone (trichloroacetic acid-precipitated, 3·68mg./ml.) inhibited destruction of labelled hormone. There was much less inhibition with added trichloroacetic acid-precipitated calcitonin (3·92mg./ml.) and virtually none with added pig insulin (3·80mg./ml.). Gel filtration of control medium on P6 (Bio-Gel) yielded one radioactive peak at the void volume. After incubation with microsomes three further peaks were obtained on gel filtration. Only the void-volume peak contained intact 125I-labelled parathyroid hormone, indicating that the microsomal enzyme degraded labelled hormone to a number of smaller fragments.

Iodothyronine 5′-Deiodination in Rat Kidney Microsomes: Sensitivity to Propylthiouracil*

Endocrinology ◽  
1988 ◽  
Vol 123 (6) ◽  
pp. 2774-2781 ◽  
Author(s):  
AJIT GOSWAMI ◽  
ISADORE N. ROSENBERG
Keyword(s):  
Rat Kidney ◽  
Kidney Microsomes

α-AMINO-n-BUTYRIC ACID IN TRANSAMINATION

1959 ◽  
Vol 37 (4) ◽  
pp. 599-604
Author(s):  
G. Y. N. Iyer ◽  
M. Sukumaran
Keyword(s):  
Skeletal Muscle ◽  
Butyric Acid ◽  
Direct Evidence ◽  
Rat Kidney ◽  
Transaminase Activity ◽  
Transamination Reaction ◽  
Kidney Liver

The transamination reaction between α-amino-n-butyric acid and α-keto-glutarate or pyruvate or oxaloacetate in the presence of homogenates of rat kidney, liver, heart, and skeletal muscle has been studied. Direct evidence is presented for transamination with α-ketoglutarate in the presence of the first three tissues and with pyruvate in the presence of kidney and liver. Appreciable amounts of alanine are formed in the course of transamination with oxaloacetate. Of the four tissues the liver appears to be quantitatively the most important by virtue of its mass and relatively high specific transaminase activity.

Biochemical and in vitro assessment of six enzyme preparations as potential feed additives

2000 ◽  
Vol 2000 ◽  
pp. 54-54 ◽  
Author(s):  
D. Colombatto ◽  
F. L. Mould ◽  
M. K. Bhat ◽  
E. Owen
Keyword(s):  
Enzyme Preparation ◽  
Rumen Fluid ◽  
Enzymatic Activities ◽  
Feed Additives ◽  
Cell Wall Degrading Enzymes ◽  
Enzyme Preparations ◽  
Factors Affecting ◽  
Considerable Research ◽  
In Vitro Assessment

Considerable research efforts have been directed towards the use of cell wall degrading enzymes as feed additives. However, the factors affecting the response to a certain enzyme preparation are not well understood. A better knowledge of the enzymatic activities present in the preparations and their interaction with a substrate in presence of rumen fluid is needed. The objectives of this study were to characterise the main enzymatic activities of six enzyme preparations and to evaluate them in the presence of rumen fluid, using thein vitroReading Pressure Technique (RPT).

scholarly journals Inhibition of protein synthesis by ricin: experiments with rat liver mitochondria and nuclei and with ribosomes from Escherichia coli

1974 ◽  
Vol 142 (3) ◽  
pp. 695-697 ◽  
Author(s):  
Margherita Greco ◽  
Lucio Montanaro ◽  
Francesco Novello ◽  
Cecilia Saccone ◽  
Simonetta Sperti ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protein Synthesis ◽  
Rat Liver ◽  
Ricinus Communis ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Isolated Rat Liver ◽  
Liver Nuclei ◽  
Isolated Rat ◽  
Liver Ribosomes

1. Ricin, a toxic protein from the seeds of Ricinus communis which inhibits poly(U)-directed polyphenylalanine synthesis by rat liver ribosomes (Montanaro et al., 1973), does not affect protein synthesis by isolated rat liver mitochondria. 2. The toxin is ineffective also on poly(U)-directed polyphenylalanine synthesis in reconstituted systems with ribosomes isolated from rat liver mitochondria or from Escherichia coli. 3. Ricin inhibits protein synthesis by isolated rat liver nuclei, but at concentrations much higher than those affecting rat liver ribosomes.

Factors affecting the rate of protein synthesis in lysate systems from reticulocytes

1968 ◽  
Vol 125 (2) ◽  
pp. 671-683 ◽  
Author(s):  
Stanley D. Adamson ◽  
Edward Herbert ◽  
Walter Godchaux
Keyword(s):  
Protein Synthesis ◽  
Factors Affecting

Protein synthesis by liver ribosomes from aged rats

1986 ◽  
Vol 35 (1) ◽  
pp. 47-57 ◽  
Author(s):  
Hakimuddin T. Sojar ◽  
Morton Rothstein
Keyword(s):  
Protein Synthesis ◽  
Aged Rats ◽  
Liver Ribosomes
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