Morphometric analysis of the lymph system in rat heart during myocardial infarction.

Simulation of myocardial infarction in random-bred rats showed that lymph vessels play the leading role in the drainage of the myocardium during the acute period of ischemic damage and compensate for the developing insufficiency of interstitial drainage at the expense of venous component of the coronary bed. A pronounced enlargement of the lymph collectors and I, II, and order III vessels in the left and right ventricles of the heart was detected.

[Effect of constant electric current on energy metabolism and ultrastructure of the isolated rat heart in the course of its post-ischemic reperfusion]. / Vliianie postoiannogo élektricheskogo toka na énergeticheskii metabolizm i ul'trastrukturu izolirovannogo serdtsa krysy v dinamike ego postishemicheskoi reperfuzii.

It is established, using Langendorff's perfusion method, that the constant current improves the energetic metabolism of the isolated heart during its reoxygenation. The constant current increases the intensity of the succinate oxidation, exerts a membrane stabilizing effect on the cardiomyocytes, stimulates intracellular reparative processes in the damaged myocardium.

[Ultrastructure of cardiomyocytes in the peri-infarct zone during the treatment of experimental myocardial infarct in rats using the hexapeptide dalargin]. / Ul'trastruktura kardiomiotsitov periinfarktnoi zony pri lechenii éksperimental'nogo infarkta miokarda u krys geksapeptidom dalarginom.

The experiments on white rats with induced myocardial infarction have studied the influence of dalargin on the infarction size and peri-infarction zone ultrastructure. 24 hours later the decrease in the infarction zone size was detected in rats who had received dalargin in a dose of 50 and 100 micrograms/kg. In the peri-infarction zone the increase in glycogen quantity, the lower degree of lipid infiltration, the increase in mitochondrial number and mitochondrial energy effectiveness coefficient were noted, as compared to control animals. Sarcolemma of cardiomyocytes from the peri-infarction zone in rats on dalargin was impermeable for colloidal lanthanum. The decrease in the infarction size under the effect of dalargin is explained by its influence on the survival of cardiomyocytes in the peri-infarction zone.

[Changes in the biochemical and morphological indices of structural disturbance in the peri-infarct area of the myocardium as affected by opioid peptides in an experiment]. / Izmenenie biokhimicheskikh i morfologicheskikh pokazatelei narusheniia struktury okoloinfarktnoi zony miokarda pod vliianiem opioidnykh peptidov v éksperimente.

The effect of opiate peptides (leu-enkephalin, met-enkephalin and beta-endorphin) as well as of enkephalin synthetic analogs (two tetrapeptides and dalargin hexapeptide) on the activity of blood enzymes CPK and LDG1, the scope of myocardial infarction and ultrastructure of periinfarction cardiomyocytes has been studied on 200 white outbred rats with simulated myocardial infarction. The endogenous opiate peptides and dalargin hexapeptide were found to significantly decrease CPK and LDG1 activity and to diminish the size of the infarction. The effect is related to the drugs influence on the survival of periinfarction cardiomyocytes that can be proved electron-microscopically and using colloid lanthanum test.

The role of enkephalins in the pathogenesis of acute myocardial infarction.

Finding opiate receptors in the heart, definition of their role in contractility and blood flow regulation (2) as well as our previous data on the decrease of Leu-enkephalins contents in the blood of patients with myocardial infarction (5) are the theoretical prerequisites for the elucidation of the role of Leu-enkephalins in the pathogenesis of acute myocardial infarction.

[Ultrastructure of the sinus and atrioventricular nodes in experimental myocardial infarct]. / Ul'trastruktura sinusnogo i atrioventrikuliarnogo uzlov pri éksperimental'nom infarkte miokarda.

The ultrastructure of sinus and atrioventricular nodes was studied in white rats with experimental myocardial infarction. 24 hours after the induction of the disease mitochondrial enlargement characterized by the increase in their area, decrease in the number of cristae and the decline in the rate of mitochondrial energy effectiveness was detected. Different degrees of nuclear chromatin aggregation and membrane permeability for colloidal lanthanum were observed. Characteristic types of conduction cellular lesions were revealed in experimental myocardial infarction.