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Biomedical subjects

O N Terpilovskaia

Publications and source records attributed to O N Terpilovskaia.

9 recordsLinked to original sources
PubMed1987

[DNA repair in mammalian nerve cells. I. DNA synthesis in the neocortex of rats induced by gamma irradiation].

A study was made of the DNA synthesis in cerebral cortex of rats, aged 14 and 60 days, after gamma-irradiation in vivo in a dose of 7 Gy, the 3H-thymidine incorporation into DNA being determined.137 Cs-radiation induces additional DNA synthesis in the neocortex tissue and in neurons. In the cortex of 14 day-old rats, the induced DNA synthesis stops 2 hours after irradiation, whereas in the cortex of 60 day-old rats and in neurons of rats of both the age groups DNA synthesis is proceeding for 3-3.5 hours. Specificity of DNA reparation processes in non-dividing cells is discussed.

Aging↗
PubMed1987

[Mechanism of action of DNAse from the rat brain].

The mechanism of action of exodeoxyribonuclease from rat brain predominantly localized in neuronal nuclei was studied. The enzyme which is highly specific towards one-chain DNA can effectively hydrolyze the two-chain DNA of plasmid pBR 322 "activated" by the disruption of the phosphodiester bond in one chain. A kinetic analysis of DNA hydrolysis with a tritium label evenly distributed along the DNA molecule and terminally labeled with phosphate revealed that the enzyme hydrolyzes polynucleotides from the 5'-to the 3'-end via a partially processive mechanism.

Animals↗
PubMed1982

[Characterization of DNAse from rat brain].

Using gel filtration and ion exchange chromatography, a DNAse specific to a single-stranded DNA was isolated from the soluble fraction of rat brain nuclear proteins. The nuclear nuclease corresponds to alkaline DNAse obtained earlier from the intact brain. The enzyme is a Mg2+- or Mn2+-dependent exodeoxyribonuclease and hydrolyzes at the same rates the ss-DNAse from rat brain, calf thymus, E. coli and poly (dA). The major products of hydrolysis are nucleoside-5'-monophosphates. A possible role of the enzyme in reparation of neuronal DNA is discussed.

Animals↗
PubMedDate not supplied

[Nucleases of cell fractions of rat brain tissues].

Nucleases are found in different fractions of nerve cells in the rat brain. The nuclease denaturating preferably the one-chain DNA at pH 8.0 is located chiefly in the neuron nuclei. Fractions of cell nuclei containg mainly neuron nuclei or glial nuclei were obtained by the method of ultracentrifugation within the sucrose gradient.

Animals↗
PubMedDate not supplied

[Nuclear DNAse from rat brain].

Nuclear DNase specific for single-stranded DNA was obtained from the rat brain. The enzyme was isolated from a soluble protein fraction of total cell nuclei using gel filtration and ion-exchange chromatography. Nuclear DNase is Mg2+-dependent exodeoxyribonuclease and hydrolyzes homological, heterological and synthetic substrate at the same rate. It is established that nucleoside-5'-monophosphates are the major product of native and synthetic polydeoxyribonucleotides hydrolysis. It is supposed that the enzyme participates in reparation of neuron DNA.

Animals↗
PubMedDate not supplied

[Permeation of pancreatic ATPase through the blood-brain barrier into the cerebral parenchyma].

Penetration of exogenous RNAases, native and albumin polymer-bound, from circulation into the brain parenchyma was studied. Native pancreatic RNAase was found to extend through the hematoencephalic barrier; maximal enzymatic activity was detected within 15-30 min after administration into a rat tail vein. The enzyme activity was not observed within 90 min both in blood serum and brain tissue. The conjugate of RNAase and human albumin with molecular mass of 300,000 penetrated through the hematoencephalic barrier. Maximal enzymatic activity was estimated within 3-5 hrs after administration and maintained rather high within 24 hrs in blood and brain parenchyma. This suggests that the preparations of this kind are promising in experimental medicine.

Albumins↗
PubMedDate not supplied

[DNAse-I inhibition by the chromatin proteins of the brain cells in rats].

The effect of protein extracted from nuclei of brain cells on the reaction of DNA-ethidium bromide complex interaction with DNAase I and Bac. subtilis nuclease was studied. The nuclei were isolated from the brain of Wistar male rats weighting 180-200 g. The fluorescence was recorded on a Hitachi MPF-44B spectrofluorimeter. Proteins extracted from the nuclei with 0.6 NaCl substantially inhibited the DNAase I but not Bac. subtilis nuclease activity. Other studied fractions of nuclei lacked the capacity for inhibiting DNAase I.

Animals↗