[Computer simulation of ESR signals of liver paramagnetic centers]. / Modelirovanie s pomoshch'iu EVM signalov EPR paramagnitnykh tsentrov pecheni.

Changes of paramagnetic centres concentration characterized by g-factors values of 1.94, 2.2, and 2.03 in the rat liver were studied by ESR method under acute intoxication by diethylnitrosamine (DENA) and at preliminary threefold treatment of animals with butylhydroxytoluene (BHT). A protective effect of BHT can be explained by its stabilizing action of the membrane structures. A comparison has been carried out with a similar study of paramagnetic centres in the experiment of chronic intoxication by DENA. A simulation was performed of the liver tissue ESR spectra by means of special computer program. The parameters of simulated ESR spectra of the liver tissue with due regard for ESR signal g 2.03 corresponded to the parameters of the experimental spectra. Confirmations were obtained for the nature and number of paramagnetic centres in the liver tissue.

Investigation of membrane proteins in rat erythrocytes in spontaneous hypertension by means of spin-label technique.

It has been suggested that alterations in cell membrane proteins may play a role in changes of erythrocyte membrane structure and function in hypertension. In order to characterize the structure of membrane proteins of erythrocytes from spontaneously hypertensive rats (SHR) the spin-label technique with a maleimide spin-label was used. A significant difference was observed in the characteristic electron-spin resonance (e.s.r.) spectrum of the label between samples from normotensive rats and SHR. The difference was eliminated and the spectrum significantly changed after treatment of the labelled membrane with EDTA followed by washing out the EDTA extracts, whereas the same treatment with EDTA without the following washing had no effect on the e.s.r. spectrum. It is concluded that the EDTA extracts different substances in the different rat groups. The spin-label technique is a useful method for distinguishing cell membrane properties in SHR and normotensive rats.

[Computer modeling of ESR spectra of the plasma in patients with Down's syndrome]. / Modelirovanie s pomoshch'iu EVM spektrov EPR plazmy krovi u bol'nykh s sindromom Dauna.

ESR technique at 77 degrees K was used for studying the blood plasma ESR signals of patients with Down syndrome and of healthy people. It was observed that the first exhibited a tendency towards a decrease of ESR signal with g = 4.3 and increase of the ratio of ceruplasmin (g = 2.05) and transferrin (g = 4.3) ESR signal amplitude. A computer simulation has been carried out by means of special mathematical program of experimental ESR spectra of the blood plasma.

[Study of the structure of erythrocyte membrane in spontaneous genetic hypertension using the spin-label method]. / Izuchenie struktury membranyéritrotsitov pri spontannoi geneticheskoi gipertenzii metodom spinovykh metok.

An analysis of ESR spectra of maleimid spin-labeled erythrocyte membranes of spontaneously hypertensive rats of SHR line and normotensive rats of the control line WKY showed differences in the structure of membrane proteins in the norm and pathology. These differences were compared with the differences between the erythrocyte membranes of SHR and WKY, found earlier by fluorescent probe method. An important role of membrane peripheric proteins in the appearance of the above differences in suggested.

[Free radicals and oxidative phosphorylation in chemical carcinogenesis]. / Svobodnye radikaly i okislitel'noe fosforilirovanie pri khimicheskom kantserogeneze.

Rat liver mitochondria were investigated at DEN induced chemical cancerogenesis. The intensity of ESR signal (g = 2.00) at 77 K was measured in parallel with respiratory control indicating the relationship between oxidation and ATP synthesis levels. Correlation between these values was obtained. Consequently the change of ESR signal (g = 2.00) intensity at cancerogenesis may be to a great extent associated with the state of the coupling system in mitochondria.

[Electron paramagnetic resonance spectra with g=2.03 of the animal liver tissue treated with butylhydroxytoluene and diethylnitrosamine]. / Spektry élektronnogo paramagnitnogo rezonansa s g=2,03 tkanei pecheni zhivotnykh pri deistvii butilgidroksitoluola i diétilnitrozamina.

ESR spectra g=2.03 intensities of rat liver tissues were studied under the action of cancer agent either diethylnitrosamine (DEN) with butylhydroxytoluene (BHT) injected before DEN or without BHT at 77 K. Combined influence of DEN and BHT upon the intensity change of ESR spectra with g=2.03 at animal disease is explained by modified action of DEN metabolism.