scholarly journals Effect of a nutritional shift on the degradation of abnormal proteins in the mouse liver. Decreased degradation during rapid liver growth

1977 ◽  
Vol 164 (2) ◽  
pp. 363-369 ◽  
Author(s):  
R Amils ◽  
R D Conde ◽  
O A Scornik
Keyword(s):  
Protein Degradation ◽  
Size Distribution ◽  
Intravenous Injection ◽  
Mouse Liver ◽  
Liver Protein ◽  
Large Decrease ◽  
General Phenomenon ◽  
Liver Growth ◽  
Selective Degradation ◽  
Total Liver

1. The intravenous injection of puromycin to mice 0.5 min after administration of radioactive leucine resulted in the release of labelled ribosome-bound nascent protein chains with the next 0.5 min. 2. During the subsequent 13 min, 40% of the liver protein radioactivity disappeared. The rate of this process was already maximal 0.5 min after the injection of puromycin, with no apparent lag. 3. Evidence is presented that this phenomenon represents the selective degradation of puromycinyl-peptides: (a) the magnitude of this fraction corresponded to the calculated proportion of protein radioactivity in nascent chains at the time of the puromycin effect; (b) the size distribution of the proteins disappearing between 2 and 14 min was smaller than that of those retained at 14 min; and (c) when the injection of puromycin was delayed for 5 min, or when the leucine pulse was interrupted by the injection of cycloheximide (rather than puromycin), the fraction disappearing within 14 min was much smaller. 4. The degradation of puromycinyl-peptides was much slower in the rapidly growing livers of animals recovering from a protein depletion than in the protein-depleted controls. It is concluded that the large decrease in the overall rates of total liver protein degradation previously described during liver growth is a general phenomenon, also affecting the rate of scavenging of abnormal proteins.

scholarly journals Role of protein degradation in the growth of livers after a nutritional shift

1976 ◽  
Vol 158 (2) ◽  
pp. 385-390 ◽  
Author(s):  
R D Conde ◽  
O A Scornik
Keyword(s):  
Protein Synthesis ◽  
Protein Degradation ◽  
Liver Protein ◽  
Protein Ratio ◽  
Liver Growth ◽  
Adequate Diet ◽  
Rapid Restoration ◽  
The Difference ◽  
Net Protein

Fractional rates of synthesis and degradation of liver porteins were estimated during the rapid restoration of liver mass observed in protein-depleted mice when they are fed with an adequate diet. 1. Net protein gain was fastest 12h after the nutritional shift, when it reached a rate of 48% per day. 2. The RNA/protein ratio in livers of protein-depleted animals was essentially the same as in normal livers; it increased by a maximum of 13% 12h after the nutritional shift. 3. Rates of protein synthesis in vivo were measured by the incorporation into liver protein of massive amounts of L-[1-14C]leucine. In protein-depleted animals, the rate of synthesis per mg of RNA was 72% of that in normal livers. Normal rates were recovered within 12h of the nutritional shift. 4. The fraction of newly synthesized protein retained by the liver was studied after they were pulse-labelled by the intravenous injection of radioactive leucine, and, 5 min later, pactamycin (an inhibitor of the initiation of protein synthesis); 3h later the livers in both experimental situations retained 58% of the newly synthesized protein. 5. Fractional rates of protein degradation were estimated either from the difference between the synthesis of stable liver proteins and the net protein increase, or by the disappearance of radioactivity from the liver protein previously labelled by the administration to the mice of NaH14CO3. Both procedures demonstrated a large decrease in the rate of protein degradation during liver growth.

Turnover of total proteins and ornithine aminotransferase during liver regeneration in rats

1980 ◽  
Vol 238 (1) ◽  
pp. E46-E52
Author(s):  
S. L. Augustine ◽  
R. W. Swick
Keyword(s):  
Amino Acids ◽  
Liver Regeneration ◽  
Protein Degradation ◽  
Partial Hepatectomy ◽  
Free Amino ◽  
Liver Protein ◽  
Ornithine Aminotransferase ◽  
Fractional Rate

The recovery of approximately 40% of the total liver protein during the first day after partial hepatectomy was shown to be due to the near cessation of protein breakdown rather than to an increase in protein synthesis. The decrease in degradation of total protein was less if rats were adrenalectomized or protein-depleted prior to partial hepatectomy. The effect of these treatments originally suggested that changes in free amino acid levels in liver might be related to the rate of protein degradation. However, no correlation was found between levels of total free amino acids and rates of breakdown. Measurements of individual amino acids during liver regeneration suggested that levels of free methionine and phenylalanine, amino acids that have been found to lower rates of protein degradation in vitro, are not correlated with rates of breakdown in vivo. The difference between the fractional rate of ornithine aminotransferase degradation (0.68/day and 0.28/day in sham-hepatectomized and partially hepatectomized rats, respectively) was sufficient to account for the higher level of this protein 3 days after surgery in the latter group.

Inhibition of liver protein synthesis during laparoscopic surgery

1999 ◽  
Vol 277 (4) ◽  
pp. E591-E596 ◽  
Author(s):  
Hans Barle ◽  
Björn Nyberg ◽  
Stig Ramel ◽  
Pia Essén ◽  
Margaret A. McNurlan ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Laparoscopic Surgery ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Liver Protein ◽  
Early Group ◽  
Total Liver ◽  
Elective Laparoscopic Cholecystectomy ◽  
Absolute Synthesis ◽  
Late Group

Previous studies have indicated that laparoscopic surgery is associated with a decline in liver protein synthesis. In this study, the fractional synthesis rate (FSR) of total liver protein and albumin was measured in patients undergoing elective laparoscopic cholecystectomy at different times after commencing the procedure ( n = 8 + 8). Liver biopsy specimens were taken after 15 min of surgery in an “early” group and after 49 min of surgery in a “late” group. The liver FSR was higher in the early group (24.1 ± 4.7%/day) compared with the late group (19.0 ± 2.8%/day, P < 0.02). The fractional and absolute synthesis rates of albumin were similar in the two groups, 6.4 ± 1.5 vs. 6.5 ± 1.0%/day and 97 ± 19 vs. 96 ± 18 mg ⋅ kg−1⋅ day−1for the early and late groups, respectively. It is concluded that laparoscopic surgery was accompanied by a decrease in total liver protein synthesis rate, which developed rapidly during surgery. In contrast, no change in the synthesis rate of albumin was apparent during the course of surgery.

DNA sequencing of a mouse liver protein that binds selenium: implications for selenium's mechanism of action in cancer prevention

1990 ◽  
Vol 11 (11) ◽  
pp. 2071-2073 ◽  
Author(s):  
Mohinder F. Bansal ◽  
Tapas Mukhopadhyay ◽  
John Scott ◽  
Richard G. Cook ◽  
Ratna Mukhopadhyay ◽  
...  
Keyword(s):  
Dna Sequencing ◽  
Cancer Prevention ◽  
Mechanism Of Action ◽  
Mouse Liver ◽  
Liver Protein

STUDIES ON CORTICOSTERONE C-20 REDUCTION IN THE MOUSE

1962 ◽  
Vol 40 (1) ◽  
pp. 1797-1810 ◽  
Author(s):  
R. E. Krehbiel ◽  
A. F. Burton ◽  
Marvin Darrach
Keyword(s):  
Intravenous Injection ◽  
Mouse Liver ◽  
Enzyme Preparation ◽  
Soluble Fraction ◽  
Reductase Activity ◽  
Kinetics Of

The intravenous injection of corticosterone in the mouse was followed by liver assays for corticosterone and 20α- and 20β-dihydrocorticosterone. The 20α-epimer proved to be the more abundant product. Corticosterone 20α-reductase activity of mouse liver was shown to be associated with the dialyzed soluble fraction of the cell which served as an enzyme preparation for a study of certain properties of corticosterone 20α-reductase and the kinetics of the forward and reverse reactions.

scholarly journals The synthesis rates of total liver protein and plasma albumin determined simultaneouslyin vivoin humans

Hepatology ◽  
1997 ◽  
Vol 25 (1) ◽  
pp. 154-158 ◽  
Author(s):  
H. Barle ◽  
B. Nyberg ◽  
P. Essén ◽  
K. Andersson ◽  
M. A. McNurlan ◽  
...  
Keyword(s):  
Liver Protein ◽  
Plasma Albumin ◽  
Total Liver

scholarly journals Decreased protein and puromycinyl-peptide degradation in livers of senescent mice

1982 ◽  
Vol 202 (1) ◽  
pp. 47-51 ◽  
Author(s):  
L Lavie ◽  
A Z Reznick ◽  
D Gershon
Keyword(s):  
Protein Degradation ◽  
Proteolytic Activity ◽  
Trichloroacetic Acid ◽  
Liver Protein ◽  
Native Proteins ◽  
Age Related ◽  
Degradation Rates ◽  
Time Required ◽  
Old Mice ◽  
Related Increase

Liver protein-degradation rates were determined in young and old C57B1 mice by the method of Swick & Ip [(1974) J. Biol. Chem. 249, 6836-6841]. The results indicated a marked age-related increase in the half-lives of short-lived proteins in the nuclear, mitochondrial, lysosomal and 100000 g-supernatant cellular fractions and in total trichloroacetic acid-precipitable proteins. The efficiency of the degradation system in removing aberrant proteins from livers of young and old mice was tested. The time required for 50% disappearance of puromycinyl-peptides changed from about 20 min in 6-month-old mice to approx. 150 min in 24-month-old animals. These findings suggest that in old animals the proteolytic activity involved in degradation of aberrant proteins, and presumably of "native proteins, is markedly defective.

scholarly journals Inhibition of polyamine accumulation and deoxyribonucleic acid synthesis in regenerating rat liver

1976 ◽  
Vol 158 (2) ◽  
pp. 485-488 ◽  
Author(s):  
H Pösö ◽  
J Jänne
Keyword(s):  
Partial Hepatectomy ◽  
Ornithine Decarboxylase ◽  
Rat Liver ◽  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
Liver Protein ◽  
Polyamine Synthesis ◽  
Total Liver ◽  
Regenerating Rat Liver ◽  
Deoxyribonucleic Acid Synthesis

Repeated injections of 1,3-diaminopropane into rats after partial hepatectomy caused a repression-type inhibiton of liver ornithine decarboxylase (EC 4.1.1.17) and totally prevented the marked increases in liver putrescine and spermidine concentrations that normally occur in response to partial hepatectomy. The inhibition of polyamine synthesis by diaminopropane was accompanied by a profound decrease (about 80%) in the synthesis of DNA in the regenerating rat liver without any changes in the synthesis of RNA and total liver protein.

Quantitative reproducibility of measurements from Coomassie Blue-stained two-dimensional gels: Analysis of mouse liver protein patterns and a comparison of BALB/c and C57 strains

1985 ◽  
Vol 6 (12) ◽  
pp. 592-599 ◽  
Author(s):  
N. Leigh Anderson ◽  
Sharron L. Nance ◽  
Sandra L. Tollaksen ◽  
Frederic A. Giere ◽  
Norman G. Anderson
Keyword(s):  
Mouse Liver ◽  
Liver Protein ◽  
Two Dimensional ◽  
Protein Patterns ◽  
Coomassie Blue
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