Pdy ( Adenosine Dighosphate Ribose ) Polymerase in Regenerating Rat Liver and in Other Tissues
نویسنده
چکیده
Poly(ADP-ribose) polymerase activity was determined in liver nuclei isolated from partially hepatectomized rats and was compared with the activity in sham-operated animals. There were minor, time-dependent variations in enzyme activities, which, however, do not seem to be related to DNA formation or mitosis. When adult and neonatal rat liver nuclei were compared, again very similar polymerase activities per unit of DNA were obtained. On the other hand, by using a new enzyme test based on the solubilization of the enzyme by 0.5 M-NaCl (Gill, 1972), different results were obtained pointing to an apparently higher activity in neonatal versus adult liver. I t could be shown that the difference arose from inhibiting factors present in different amounts in proliferating and non-proliferating tissues. Thus no correlation of poly(ADP-ribose) polymerase activity and proliferation rate exists in hepatic tissues.
منابع مشابه
Labeling of glucose, ribose, and deoxyribose by 1- and 2-C14-glycine in regenerating rat liver.
The present study was intended to provide information on the carbon sources of deoxyribose in animal tissues. Some tracer studies (2-5) have indicated that ribose of certain nucleosides or nucleotides is converted to deoxyribose without rupture of the nucleosidic linkage. However, evidence from cell-free preparations of animal tissues (6, 7) as well as microorganisms (6) has suggested an origin...
متن کاملDNA polymerases I and II in regenerating rat liver and Morris hepatomas.
Two nonmitochondrial forms of DNA polymerase are demonstrated in regenerating rat liver and Morris hepatomas 7777, 7800, and 7794A. The enzymes have been partially purified from subcellular fractions of these tissues. The purification procedure involves fractionation with ammonium sulfate and chromatography on diethylaminoethyl cellulose and on phosphocellulose. The enzymes have different physi...
متن کاملNovel Poly(Adenosine Diphosphate-Ribose) Polymerase (PARP) Inhibitor, AZD2461, Down-Regulates VEGF and Induces Apoptosis in Prostate Cancer Cells
Background: Prostate cancer (Pca) is a heterogeneous disease, and current treatments are not based on molecular stratification. Poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) inhibitors have recently been found to be remarkably toxic to cells with defects in homologous recombination, particularly cells with BRCA-mutated backgrounds. Therefore, this preliminary study was designed to ...
متن کاملMultiple forms of mammalian deoxyribonucleic acid polymerase. An attempt to relate their interactions with nuclei and free deoxyribonucleic acid in vitro with their possible functions in vivo.
THE DNA POLYMERASES OF THE FOLLOWING EUKARYOTIC TISSUES WERE STUDIED: regenerating rat liver, normal rat liver, rat thymus, normal mouse liver and Ehrlich ascites-tumour cells. In all cases two main polymerase forms are observed, one of mol.wt. 200000, preferring denatured DNA to native calf thymus DNA primer, designated type I, and the other, designated type II, of mol.wt. 100000, showing a va...
متن کاملPancreatic β-Cell Death, Regeneration and Insulin Secretion: Roles of Poly(ADP-Ribose) Polymerase and Cyclic ADP-Ribose
In the early 1980s, we proposed a unifying model for beta-cell damage (The OKAMOTO model), in which poly(ADP-ribose) synthetase/polymerase (PARP) activation plays an essential role in the consumption of NAD+, which leads to energy depletion and necrotic cell death. In 1984, we demonstrated that the administration of PARP inhibitors to 90% depancreatized rats induces islet regeneration. From the...
متن کامل