[Chromatin ultrastructure in hepatocyte nuclei of dogs as affected by adrenaline]. / Ul'trastruktura khromatina v iadrakh gepatotsitov sobaki pod vliianiem adrenalina.

The study of the chromatin's ultrastructure in the nuclei of hepatocytes under the adrenalin influence is very essential (e.g., the square of the perimembrane chromatin-PmCh). The experiments have been carried out on 10 male dogs. Experimental dogs received adrenalin intravenously--100 mkg per 1 kg of weight during 5 days. The pieces of tissue have been fixed by 2.5% glutaraldehyde solution ("Serva"--FRG) and postfixed by 2% four-oxide osmium, dehydrated in spirts and acetone, and poured into exposed mixtures. The ultrathin cuts have been got on ultramicrotome "LKB" (Sweden) Microscopic sections examined by electronic microscope "JEM-7" (Japan) increasing 10,000 times. Morphonutrical working have been carried out by Student method and expressed in conventional units. The relation of the area of perimembrane chromatin to the nucleus's area in hepatocytes of the controlled animals, is equal--to 0.21 and of the experimental ones--to 0.13 (decreased 1.6 times, 0.02 p 0.05).

[Ultrastructure of chromatin in nuclei of hepatocytes of regenerating guinea pig liver after administration of vitamin B12]. / Ul'trastrutktura khromatina v iadrakh gepatotsitov regeneriruiushchei pecheni morskoi svinki pri vvedenii vitamina B12.

Experiments have been carried out on 10 male guinea-pigs (0.5 kg, 6 month old). The experimental animals have been submitted to partial hepatectomy of the left lobe of the liver (lobus externus sinister) with and without the administration of vitamin B (0.8 mgr/kg). 10 nuclei of hepatocytes have been expressed in conventional units.

[Electron-microscopic study of chromatin in nuclei of canine cardiomyocytes as affected by adrenaline]. / Elektronno-mikroskopicheskoe issledovanie khromatina v iadrakh kardiomiotsitov sobaki pod vliianiem adrenalina.

The study of the chromatin's ultrastructure in the nuclei of cardiomyocytes under the adrenalin influence is very essential (e. g., the square of the perimembrane chromatin-PmCh). The experiments were carried out on 10 male-dogs. Experimental dogs had been receiving adrenalin intravenously--100 mkg per 1 kg of weight during 5 days. The pieces of tissue were fixed by 2.5 percent glutaraldehyde solution ("Serva"-USA) and were postfixed by 2 percent four-oxide osmium, were dehydrated in spirits and acetone, were poured into epoxide mixtures. Microscopic sections were examined with electronic microscope IEM-7 (Japan) increase in 10,000 times. Morphometrical working was carried out by Student method and expressed in conventional units. The PmCh area's relation to the nucleus's area in cardiomyocytes of the controlled animals, equal to 0.10 (10%) and of the experimental ones-0.05 (5%). Thus, the difference in 2 times (P < 0.001) discovered by the electronic microscopy method in dense PmCh areas of cardiomyocytes' nuclei at controlled and experimental animals evidently associated with chromatin's reorganization.

[DNA methylation in human lung tumors]. / Metilirovanie DNK v opukholiakh legkikh cheloveka.

Nucleotide profile and level of methylated cytosine (5-MC) were evaluated in DNA obtained from lung tumors in males. The level of 5-MC in DNA in malignant tissue (1.7 +/- 0.1 mol%) was half as much again that of normal lung (1.1 +/- 0.1 mol%), the difference being statistically significant.

[Effect of tamponade on the nucleotide composition and cytosine methylation level of DNA in the heart muscle of dogs]. / Vliianie tamponady na nukleotidnyi sostav i uroven' metilirovaniia tsitozina DNK v myshtse serdtsa sobak.

Base composition and quantitative changes in the 5-methylcytosine (m5c) content in DNA isolated from male dogs' heart muscle under the acute tamponade have been studied. Due to the effect of tamponade statistically reliable decrease (15%) in m5c content in DNA has been found to take place in experiment in comparison with control. Possible mechanisms of DNA methylation decrease by cytosine are under discussion.

[Effect of adrenaline on nucleotide composition and the degree of DNA methylation in the canine myocardium]. / Vliianie adrenalina na nukleotidnyi sostav i stepen' metilirovaniia DNK v serdechnoi myshtse sobak.

Nucleotide composition and changes of 5-methylcytosine content (m5C) in DNA isolated from male-dogs' cardiac muscle (stomach) under the influence of adrenalin have been studied. After slow intravenous injection of adrenalin in extremal doses (7 mg during 5 days) quantity of m5C in DNA decreases in 1,2 times in comparison with the control. Is has been suggested that the decrease of DNA methylation by cytosine is possible as a result of increase of enzyme activity demethylizing DNA by cytosine and (or) inactivation of methilase specifically methylizing DNA by cytosine.

[Effect of vitamin B12 on liver and kidney DNA methylation in guinea pigs in the presence of methionine and ATP]. / Vliianie vitamina B12 na metilirovanie DNK pecheni i pochek morskikh svinok v prisutstvii metionina i ATF.

Changes of 5-methylcytosine (m5C) content in DNA of guinea-pigs' liver and kidney under the influence of vitamin B12 in the presence of methionine and ATP have been studied. After B12 injection m5C quantity in liver DNA increases in 1,4 times, in kidney DNA in 1,6 times. The methionine and ATP injection lowers B12 effect on the DNA methylation in liver and kidney.

[Nucleotide composition and the methylated cytosine level in the DNA from a cancerous stomach tumor]. / Nukleotidnyi sostav i uroven' metilirovannogo tsitolizina v DNK iz rakovoi opukholi zheludka.

Under study was the nucleotide content and the level of methylated cytosine (5-MC) in the DNA, isolated from adenocarcinoma of the stomach, gastric mucosa in patients with duodenal ulcer as well as from the mucosa of intact human stomach. The difference (reliable statistically) was found in the amount of 5-MC between the tissues concerned. So, in adenocarcinoma the amount of 5-MC was 4.64 +/- 0.3 mol.%, in gastric mucosa in case of duodenal ulcer--2.63 +/- 0.3 mol.%, while in mucosa of intact stomach--1.52 +/- 0.3 mol.%. The increased level of DNA methylation should influence its structure and activity.