NUCLEODEPOLYMERASE ACTIVITY IN REGENERATING RAT LIVER

1952 ◽  
Vol 30 (3) ◽  
pp. 180-184
Author(s):  
Roger Daoust ◽  
Gaston de Lamirande ◽  
Antonio Cantero
Keyword(s):  
Liver Injury ◽  
Enzymatic Activity ◽  
Partial Hepatectomy ◽  
Rat Liver ◽  
Azo Dye ◽  
Time Intervals ◽  
Constant Amount ◽  
Average Cell ◽  
Regenerating Rat Liver

The desoxyribonucleodepolymerase and ribonucleodepolymerase activity has been estimated in rat liver at various time intervals following partial hepatectomy. When expressed per a constant amount of nitrogen of the tissue, as routinely done, the activity of these enzymes shows significant variations in regenerating rat liver. However, these variations are no longer evident when the enzymatic activity is recalculated “per cell” and it is concluded that they do not reflect actual variations of enzymatic activity in the average cell of the regenerating rat liver. Presumably, the increase in activity of the two nucleode-polymerases, previously observed in liver of rats fed p-dimethylaminoazobenzene, should be attributed to the liver injury by the azo dye rather than to the ensuing regeneration with ultimate hepatoma formation.

RIBONUCLEASE ACTIVITY IN REGENERATING RAT LIVER

1967 ◽  
Vol 45 (7) ◽  
pp. 1021-1026 ◽  
Author(s):  
D. J. S. Arora ◽  
G. de Lamirande
Keyword(s):  
Enzymatic Activity ◽  
Liver Regeneration ◽  
Partial Hepatectomy ◽  
Rat Liver ◽  
Ribonucleic Acid ◽  
Ribonuclease Activity ◽  
Regenerating Liver ◽  
Early Stages ◽  
Regenerating Rat Liver ◽  
Ribonucleoprotein Particles

Ribonucleoprotein particles were isolated from sham-hepatectomized and partially hepatectomized animals. The levels of ribonucleic acid and of proteins, as well as the ribosomal ribonuclease activity, have been studied in regenerating liver at periods of 4, 8, 16, 36, and 72 hours after partial hepatectomy. The results showed that the amount of ribosomes in regenerating rat liver was not affected as compared with the level observed in sham-operated rats. However, a decrease of ribonuclease activity was noticed in the early stages of liver regeneration. The ribonuclease activity was practically negligible at 16 and 36 hours. Less than 50% of the enzymatic activity was regained at the 72-hour period after partial hepatectomy.Results show that the ribosomes from regenerating liver are more stable and the stabilizing factor seems to be the absence of ribonuclease.

DEOXYCYTIDYLATE DEAMINASE LEVELS IN REGENERATING RAT LIVER

1961 ◽  
Vol 39 (6) ◽  
pp. 1043-1054 ◽  
Author(s):  
D. K. Myers ◽  
C. Anne Hemphill ◽  
Constance M. Townsend
Keyword(s):  
Dna Synthesis ◽  
Liver Regeneration ◽  
Partial Hepatectomy ◽  
Rat Liver ◽  
Deoxyribonucleic Acid ◽  
Regenerating Liver ◽  
Regenerating Rat Liver ◽  
High Level ◽  
Early Regeneration

Deoxycytidylate deaminase activity and net synthesis of deoxyribonucleic acid (DNA) in vivo were found to increase at approximately the same time during the early stages of liver regeneration. However, deaminase activity in the regenerating liver remained at a high level for 1 day after DNA synthesis had slowed down again during the later stages of regeneration. The increase in deaminase activity was restricted as a result of exposure to 600 r X radiation during early regeneration, but this effect only became evident 11–16 hours after the irradiation. Irradiation on the second day after partial hepatectomy, when deaminase levels in control regenerating livers were relatively constant, failed to affect the deaminase activity immediately but did produce a 40–50% decrease in activity 11–16 hours later. Other antimitotic agents, e.g., colchicine, had little effect on deaminase activity.

Upregulation of Escherichia coli heat-stable enterotoxin receptor in regenerating rat liver

1994 ◽  
Vol 266 (5) ◽  
pp. G899-G906 ◽  
Author(s):  
D. W. Laney ◽  
J. A. Bezerra ◽  
J. L. Kosiba ◽  
S. J. Degen ◽  
M. B. Cohen
Keyword(s):  
Escherichia Coli ◽  
Mrna Expression ◽  
Partial Hepatectomy ◽  
Rat Liver ◽  
Acute Phase ◽  
Chloride Secretion ◽  
Hepatocyte Proliferation ◽  
Heat Stable ◽  
Hepatocyte Regeneration ◽  
Regenerating Rat Liver

Guanylate cyclase C (GC-C) is a transmembrane protein that serves as a receptor for the recently characterized endogenous ligand guanylin and for Escherichia coli heat-stable toxin (STa). Binding of either guanylin or STa to intestinal GC-C results in net chloride secretion. Although GC-C is expressed in the rat intestine throughout life, its expression in the rat liver has previously been shown to occur only during the perinatal period. As a step toward elucidating the role of this receptor in the liver, we tested the hypothesis that GC-C mRNA expression could be induced in the adult rat liver following 1) partial hepatectomy, a stimulus for hepatocyte proliferation; 2) intraperitoneal carbon tetrachloride injection, a model of hepatocyte regeneration in the presence of inflammatory changes; and 3) subcutaneous turpentine injection, which generates an acute phase response without hepatocyte proliferation. We demonstrated expression of GC-C mRNA in the regenerating rat liver following either partial hepatectomy or CCl4-induced hepatic necrosis. We have also shown that GC-C mRNA expression occurred in association with an acute phase reaction. Coordinate with the expression of GC-C mRNA, there was upregulation of radiolabeled STa binding to liver plasma membranes prepared from turpentine-treated rats. Maximal expression of GC-C occurred in preparations enriched for the canalicular domain. Although the function of GC-C in the liver is unknown, localization to the canalicular domain would be consistent with a role for GC-C in hepatic chloride secretion, especially in the perinatal liver and during hepatocyte regeneration.

scholarly journals Thymidine metabolism in regenerating rat liver one to two hours after partial hepatectomy

1973 ◽  
Vol 136 (3) ◽  
pp. 571-577 ◽  
Author(s):  
Margery G. Ord ◽  
Lloyd A. Stocken
Keyword(s):  
Partial Hepatectomy ◽  
Intravenous Injection ◽  
Rat Liver ◽  
Thymidine Uptake ◽  
Regenerating Rat Liver ◽  
Perfusion Studies ◽  
Saturation Kinetics

1. When [3H]thymidine was injected intravenously into rats in amounts up to 40mg/kg body wt. and the3H radioactivity in the livers measured at 30min, saturation kinetics for thymidine uptake were not found. If the animals were examined 3 min after intravenous injection, saturation could be attained in normal rats with 12mg of thymidine/kg and in partially hepatectomized rats with 4mg/kg. At concentrations of thymidine close to saturation, no differences were found in rate or amount of uptake/g of liver between normal and partially hepatectomized rats 1–2h after operation. 2. Perfusion techniques were used to compare thymidine uptakes in the two sets of rats at concentrations up to 40μm-thymidine. Uptakes with tracer amounts of thymidine after 30min were identical in vivo and in the perfusion studies and were twice as great in livers from partially hepatectomized rats with concentrations up to 40μm-thymidine. 3. At 1.5h after operation there was nearly twice as much β-aminoisobutyrate present per g of liver from partially hepatectomized as compared with normal rats.

Proton nuclear magnetic resonance of regenerating rat liver after partial hepatectomy

Life Sciences ◽  
1982 ◽  
Vol 31 (6) ◽  
pp. 505-508 ◽  
Author(s):  
Jacques D. de Certaines ◽  
Jacques P. Moulinoux ◽  
Laurence Benoist ◽  
Anne-Marie Bernard ◽  
Paulette Rivet
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Partial Hepatectomy ◽  
Rat Liver ◽  
Proton Nuclear Magnetic Resonance ◽  
Regenerating Rat Liver ◽  
Nuclear Magnetic
Sign in / Sign up

Export Citation Format

Share Document