Lipid peroxidation in the heart of adult and old rats during immobilization stress.

This study was designed to assay the lipid peroxidation (LPO) in the heart from adult (10--12 months) and old (22--25 months) Wistar male rats during immobilization stress. A value of LPO was estimated according to the concentration of conjugate dienes, TBA-positive substances and fluorescent products such as Schiff base. Investigations have shown that immobilization of rats was accompanied by increase in the concentration of all studied LPO intermediates in myocardium from both the age groups. Accumulation of these metabolites in old rat hearts was considerably higher than in adult ones. Dimethyl sulfoxide injection has limited stress-induced stimulation of LPO. Changes revealed in LPO-stimulation have different consequences in pathogenesis of stress-dependent injury in myocardium from adult and old rats. Utilization of LPO metabolites in old rats takes place mainly with formation of Schiff base. Accumulation of these products in myocardium is accompanied by modification of intracellular macromolecules and thus promotes the enhancement of stress-induced injury of myocardial cells. In adult rats during stress, the utilization of malonic dialdehyde and substances homologous to it is not accompanied by Schiff base accumulation in myocardium. It may be important for the restriction of stress-induced injury of myocardial cells.