[Changes in the activity of lipid peroxidation in the myocardium of adult and aged rats under stress]. / Izmeneniia aktivnosti perekisnogo okisleniia lipidov v miokarde vzroslykh i starykh krys pri stresse.

The levels of lipid peroxidation (LPO) products, the antioxidative system and morphometric changes were studied in the myocardium of adult (8-10-month) and old (20-24-month) male rats in different periods after their exposure to stress. The findings suggest that the maximum damaging action occurs 18-60 hours of poststress. The high activity of LPO and the low activity of the antioxidative system in the hearts of the old animals determine more substantial impact of stress on the myocardium of this group of animals.

[Effect of prostaglandin E2 on the development of myocardial damage in rats with various resistance to hypoxia]. / Vliianie prostaglandina E2 na razvitie adrenalinovogo povrezhdeniia miokarda u krys s razlichnoi ustoichivost'iu k gipoksii.

Experiments conducted on male rats with congenital high and low resistance to hypoxia (HH and LH, respectively) have revealed, that injection of prostaglandin E2 (PHE2) 15 min before the injection of adrenalin essentially decreases the activity of lipid peroxidation in myocardium as compared with animals which have been injected to only adrenalin. This modulative effect (PHE2) on the action of adrenalin was more pronounced in LH-rats. Consequently, the activity of the prostaglandin stress-limiting system determines to a great extent the organism resistance to hypoxia.

[Effect of prostaglandin E2 on the development of adrenaline-induced myocardiodystrophy]. / Vliianie prostaglandina E2 na razvitie adrenalinovoi miokardiodistrofii.

In experiments on male rats it was established, that injection of prostaglandin E2 (PGE2) before the injection of adrenaline decrease essentially the activity of peroxidation of lipids in myocardium in comparison with animals which had only injection of adrenaline. Accordingly, pH is a factor, that limited a damage of myocardium on the development of adrenaline myocardiodystrophy.

[Characteristics of morphological changes in the myocardium of rats with different degrees of hereditary resistance to hypoxia during the development of adrenaline-induced myocardial dystrophy]. / Osobennosti morfologicheskikh izmenenii miokarda krys s razlichnoi vrozhdennoi ustoichivost'iu k gipoksii pri razvitii adrenalinovoi miokardiodistrofii.

By means of polarizational microscopy method morphological changes of the cardiac muscle have been studied in highly-(HS) and poorly-stable (PS) rats to hypoxia 1 h and 1 day after injection of cardiotoxic dose of adrenaline (1.5 mg/kg of body mass). One hour after injection of adrenaline in PS animals the II-III stages of contractive myofibrillar changes are revealed, while in HS rats--the I-II stages. In 1 day in the myocardium of PS animals contractures of the III-IV degree are observed, more foci of clumping decay and myocytolysis than in HS rats. Severity of the morphological changes of the cardiac muscle after cardiotoxic dose of adrenaline essentially depends on the organism's reactivity.