[Age-related features of intracellular calcium homeostasis in rat cardiomyocites in postinfarction heart remodeling].

Research results of features of an intracellular calcium homeostasis in 4 and 12-month's rat cardiomyocites at postinfarction cardiosclerosis are presented. It is shown that the myocardium of animals in the old rats group is more susceptible to extrasystolic impacts. In the pathology conditions additional extrasystolic influences also had the expressed age specificity of inotropic response. The data testifying to almost identical dynamics of postextrasystolic cycles of intact myocardium in animals of investigated age groups has been obtained. The different postextrasystolic potentiation in the remodeled myocardium in old and young rats testified to different of sarcoplasmic reticulum ability to accumulate additional calcium ions. The conclusion was made that the myocardium of animals in the old rats group has more chance for development of hemodynamic significant disturbance of cardiac rhythm as a consequence of age-related changes processes of the electromechanical coupling in cardiomyocites.

[Effect of nonselective beta-adrenoblocker carvedilol on extrasystolic and postextrasystolic contractility in the rat myocardium after experimental infarction].

Features of the extrasystolic and postextrasystolic contractility of myocardium isolated from rats aged 4 months (group I, n = 30) and 12 months (group II, n = 30) after postinfarction remodeling of the heart (PIRH) and long-term treatment with carvedilol have been studied. Each age group included in 10 intact control animals, 10 animals with postinfarction cardiosclerosis (PICS), and 10 rats with PICS treated with carvedilol (2.1 mg/kg) during 28 days, beginning with the 45th day after coronary occlusion. The isometric contractility of myocardium was monitored at an electric stimulation frequency of 0.5 Hz. The extrasystolic effect was produced by an electric pulse applied within 0.2 - 5 s interval after the basic stimulation. It is established that the inotropic response of myocardium to the extrasystolic impulse exhibits age-dependent features both the intact rats and in the rats with PICS. The differences can be related to the age-dependent involvement of the ion-transport systems of sarcolemma and sarcoplasmic reticulum into the modulation of excitation--contractility coupling during PIRH. The long-term treatment with carvedilol led to restoration of the Ca(2+)-accumulation reserve of sarcoplasmic reticulum to the age-normal level in young animalsand decreased the risk of development of hemodynamically significant heart rate disturbances in old rats.

[The protective effect of trimetazidine on the myocardium against reperfusion injury during thrombolytic therapy of acute infarction]. / Zashchita miokarda trimetazidinom ot reperfuzionnykh povrezhdenii pri tromboliticheskoi terapii ostrogo infarkta.

Investigation of the protective action of the antiischemic drug trimetazidine (60 mg/kg) used during thrombolytic treatment of acute infarction showed that the drug effectively inhibits lipid peroxidation and reduces the degree of the reperfusive damage of myocardium, as determined from ECG (QRS index calculation) or from data on the blood creatinin phosphokinase level.

[Effect of the bioantioxidant histochrome on myocardial injury in reperfusion therapy on patients with myocardial infarction]. / Vliianie bioantioksidanta gistrokhroma na povrezhdenie miokarda pri reperfuzionnoi terapii u bol'nykh infarktom miokardom

AIM: To evaluate effects of histochrome on severity of reperfusion damage in opening of the coronary artery in patients with acute myocardial infarction (MI). MATERIAL AND METHODS: 86 acute MI patients were randomized into three groups. 26 patients of group 1 A received 100 mg histochrome 10 min before and 1 hour after intravenous bolus administration of thrombolytic streptokinase; 20 patients of group 1 B received histochrome by the same scheme on the disease day 1 followed by 100 mg/day for 10 days; 40 control patients have undergone thrombolysis without prophylactic histochrome. RESULTS: In the control group ventricular extrasystoles (VES) arose in 100% patients, in groups 1A and 1B--in 27%. The same picture was observed in relation to episodes of accelerated idioventricular rhythm. Coronary reperfusion was accompanied by fast dynamics of ST segment and ORS complex in the control group. MI focus measured by the Selvester ECG method was less in histochrome groups. After myocardial reperfusion malonic dialdehyde in the serum rose 6 times in the control groups and was slightly elevated in groups 1A and 1B. CONCLUSION: Preventive administration of histochrome before thrombolytic therapy to reperfuse myocardium diminishes reperfusion damage: inhibits activity of lipid peroxidation and development of necrosis focus in acute period of MI.

Cardioprotective effect of trimetazidine during thrombolytic therapy in patients with acute myocardial infarction.

We studied the cardioprotective effect of anti-ischemic drug trimetazidine in the thrombolytic therapy of acute myocardial infarction. Trimetazidine (60 mg/day) effectively inhibits lipid peroxidation and moderates reperfusion damage to the myocardium assessed by ECG, QRS index of damaged heart, and release of creatine phosphokinase into circulation.