[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. Availability of conformational shifts of membrane proteins of microsomes under the conditions of lipoperoxidation activation evoked by the stress is accompanied by changes of physico-chemical parameters of microsomal membranes. Changes in the membrane structure are expressed to the less extent in the microsomes of old rats liver as well, that evidences for the age-dependent differences of adaptational capacities of the organism.