[Chromatin-protective action of the biologically active preparation BTK-8L in tetrachloromethane and chlorophos poisoning].

Results obtained from the study of the interaction between the phytosteroid preparation (BTK-8L) and fractionated rat liver nuclear chromatin under conditions of the tetrachloromethane and chlorophos intoxications are described. It is shown that preventive injection of BTK-8L to the animals has a partial protective effect on transcriptionally active and repressed liver chromatin. This preparation interacts with chromatin histone proteins binding with them and changes the nucleoprotein complex structure as a results of which the chromatin fraction components become less accessible to the damaging action of tetrachloromethane and chlorophos.

[Effect of stress on lipid peroxidation and physico-chemical status of endoplasmic reticulum membranes in liver of adult and old rats].

As a result of experiments carried out on adult (6-8 months) and old (24-26 months) male rats of the Wistar line it is established that emotional-pain stress results (in one day) in essential increase in the activity of spontaneous, NADPH--and ascorbate-dependent peroxidation of lipids in the liver microsomes, which is expressed in the old animals rather than in the adult ones. The induced peroxidation of lipid six days after the stress effect remains activated in the adult rats and decreases to the control level in the old ones. Accumulation of lipoperoxidation products in the membrane structure of hepatocytes is accompanied by the changes of physico-chemical parameters of microsomal membranes, microviscosity and surface potential in particular.

[Interaction of a substance based on phytoecdysteroids (BTK-8L) with components of fractionated chromatin from intact rat liver].

Results of the study of interaction of the phytoecdysteroid preparation (BTK-8L) with fractionated rat liver nuclear chromatin were described. It was shown that the interaction resulted in the "loosening" of the histone proteins structure both in active and repressed chromatin. At the same time the reparative DNA synthesis in the repressed fraction was stimulated.

[Lipid peroxidation and calcium transport in rat liver microsomes after chlorofos poisoning and the effect of atropine and verapamil].

Structural and functional state of rat hepatocytes endoplasmic reticulum membranes intoxicated with chlorofos (0,0-dimethyl-(1-oxy-2,2,21-trichloroethylphosphonate) was studied. It was shown that in case of intoxication a breakage of the membrane Ca(2+)-transport function was accompanied by modification of the membrane phospholipid lipoperoxidation processes and by conformational change of proteins. It is established that prophylactic injection of m-cholinolytic atropine and Ca(2+)-channel antagonist verapamil lead to normalization of processes of ATP-dependent potassium ion transport and lipid peroxidation processes (LPO) in the liver microsomal membranes of intoxicated animals.

[Mechanisms of the genoprotective action of a phytoecdysteroid drug (BTK-8L) in chromatin damage by chlorofos].

Genoprotective effect of preparation BTK-8L from plant steroids at prophylactic injection to experimental animals at chromatin damage by chlorofos was revealed. Antioxidant action of the preparation, being most highly expressed in the transcriptionally active chromatin fraction, is, probably, the most likely mechanism of the action. The realization of this action might be carried out as a result of the direct binding of BTK-8L with the chromatin protein-lipid complex, which was revealed during the analysis of the model systems showing binding of the preparation with chromatin fractions in vitro.