Biomedical subjects

D A Kuznetsov

Publications and source records attributed to D A Kuznetsov.

61 records · Page 4Linked to original sources

PubMedDate not supplied

[The effect of magnesium pool isotopy on reactivation of mitochondrial ATP synthesis suppressed by 1-methyl-nicotine amide].

The ATP-generating activity of both rat myocardial mitochondria and intramitochondrial creatine phosphokinase (CPK) was examined as a function of the incubation medium magnesium pool isotopy. The in vitro systems tested were prepared from the hearts of animals treated with single injection of 1-methyl-nicotine amide (MNA) suppressing the NAD(P)-dependent reactions in vivo. The presense of the 25Mg paramagnetic cations leads to essential compensation of intramitochondrial ATP deficiency caused by the MNA induced blockade of oxidative phosphorylation. This effect is merely unreachable in those systems where the magnesium pool consists of isotopes with a zero nuclear spin (24Mg, 26Mg). The reactivation of mitochondrial ATP synthesis described here involves CPK activity which does not depends on MNA. In this case, a high efficiency of this reactivation seems to be a spin selective phenomenon which requires, predominantly, 25Mg2+ cations.

Adenosine Diphosphate↗

PubMedDate not supplied

[New mechanisms of biological effects of electromagnetic fields].

The production of ATP in mitochondria depends on the magnesium nuclear spin and magnetic moment of a Mg2+ ion in creatine kinase and ATPase. This suggests that enzymatic synthesis of ATP is an ion-radical process and thus depends on the external magnetic field (magnetobiology originates from this fact) and microwave fields, which control the spin states of ion-radical pairs and affect the ATP synthesis. The chemical mechanism of ATP synthesis and the origin of biological effects of electromagnetic (microwave) fields are discussed.

Adenosine Triphosphate↗

PubMedDate not supplied

[Substrate properties of C'-methylnucleoside triphosphates in a reaction of RNA synthesis catalyzed by Escherichia coli RNA-polymerase].

2 theta-C-methyl substituted and phosphonate analogs of UTP were prepared and together with the synthesized earlier 3'-C-methyl-UTP were investigated in the RNA synthesis reaction catalysed by Escherichia coli RNA-polymerase. Substrate properties of UTP analogs were studied in the presence of all natural triphosphates, in the absence of UTP and under conditions of soil substrate reaction. It was shown that UTP(3'CH3) is incorporated into the RNA chain and terminates further RNA elongation. Another analog UTP (2'CH3) may substitute natural UTP in RNA synthesis, but the effectivity of its incorporation is diminished. Phosphonate analog UTP(5'CH2) is a pseudoterminator of RNA synthesis. The conformational analysis of 2'- and 3'C-methylnucleosides by force-field method of calculation was carried out in order to find energetically forbidden conformations of these analogs due to the collision of bulky methyl group and a heterocyclic base. An attempt was made to fix the conformation of the substrate during its enzymatic transformation.

Base Sequence↗

PubMedDate not supplied

[Changes in lipoxygenase activity in developing granulation tissue during aseptic wound healing in rats].

Activation of lipoxygenases was found during development of granulation tissue in full-layer skin wound simulated in 100 Wistar rats and studied by means of electron paramagnetic resonance and high pressure liquid chromatography. Maximal activation of lipoxygenases within 2 and 6 days corresponded to two phases of wound healing: inflammation phase and phase of fibroblast proliferation during formation of the granulation tissue.

Animals↗

PubMedDate not supplied

[Possibility of hydromagnetic wave excitation in a physiologic aqueous solution].

Oscillation processes of Cl- and Na+ ions (the latter form aquacomplexes with 6 water molecules) existing in a constant geomagnetic field are analysed in NaCl aqueous solution. Joint solution of hydro- and electrodynamic equations gives several wave types. Hydromagnetic waves of two modes show the frequency dispersion of phase velocities. This results in the existence of two maxima of oscillation velicity in the frequencies 2-6 Hz and 20-30 Hz close to the cyclotron frequencies of ions. The hydromagnetic waves can have a large amplitude only when there is a variable disturbing force, e.g. a variable component of the magnetic field at the background of the constant field.

Magnetics↗

PubMedDate not supplied

[Chromatographic method for quantitative determination of cordycepin in rat brain tissue after intraperitoneal injection of the antibiotic].

A procedure is developed for quantitative estimation of intraperitoneally administered unlabelled cordycepin in acid soluble pool isolated from rat brain tissue. The fraction containing 2'- and 3'-deoxyriboadenosine (cordycepin) in acid soluble pool of rat brain was isolated after consecutive chromatography on columns of Dowex 1 X 8, Dihydroxyboryl-SP 500 and Sephasorb-HP. At the same time, 2'-deoxyriboadenosine was isolated from the acid soluble pool fraction of control animals. Content of the antibiotic in brain tissue was estimated by its difference in these two fractions (control/experiment).

Animals↗

PubMedDate not supplied

[A simple enzymatic method for the quantitative determination of cordycepin and [3'-deoxy]ATP in rat brain tissue].

A procedure for quantitative estimation of cordycepin (3'-deoxyadenosine), a specific inhibitor of post-transcriptional polyadenylation of pre-mRNA and of a metabolite of cordycepin 3'-deoxyATP in rat brain tissue is described. The procedure is based on evaluation of an inhibitory effect on the synthesis of polyA in vitro of total nucleoside and nucleoside and nucleoside triphosphate preparations isolated from the animal brain after cordycepin administration. Homogenates of intact animal brain were used as a source of "crude" polyA polymerase preparations.

Animals↗