[Prevention of stress disorders of myocardial contractile function using membrane protectors]

The effect of preliminary administration of the adrenoblocker inderal, the lipase inhibitor nicotinamide, and the phospholipase inhibitor chloroquine on the disturbance of the myocardium extensibility and contractile function, the decrease of its resistance to hypoxia and to the calcium excess usually caused by emotional-painful stress was studied on the isolated rat atrium. It was established that these drugs prevented the above post-stress disturbances without significant affection of control animals. Nicotinamide was found to be the most effective, its protective action on the myocardium was accompanied by the prevention of the stress-induced increase of free fatty acids in the blood. The whole complex of data suggests that together with the activation of lipid peroxidation, the activation of lipases and phospholipases the damaging action of fatty acids play a role in the stress-induced damage; it also gives bases to use the factors stabilizing the membranous lipid bilayer for the heart protection against the stress-induced damages.