[Activity of total serum creatine phosphokinase and its MB fraction in reversible coronary blood flow disorders in dogs in a chronic experiment]. / Aktivnost' obshchei syvorotochnoi kreatinfosfokinazy i ee fraktsii pri obratimykh narusheniiakh venechnogo krovotoka u sobak v khronicheskom opyte.

On a model of reversible coronary blood flow disturbances in dogs short-term myocardial ischemia (2 to 15 min) in 16 chronic experiments caused an increase in the activity of total blood CPK by 57.3 +/- +/- 11.7 mE/ml (p less than 0.001) and of MB fraction by 6.9 +/- 1.23 mE/ml (p less than 0.001). Experiments in which the disturbances in coronary blood flow were repeated at intervals of 2-3 days showed that the changes in the activity of the enzymes occurred in definite stages. The results obtained on this model present new possibilities for elaborating diagnostic criteria of microfocal myocardial lesions.

[Intracardiac nervous regulation of the systolic and diastolic activity of isolated heart ventricle]. / Vnutriserdechnaia nervnaia reguliatsiia sistolicheskoi i diastolicheskoi aktivnosti zheludochka izolirovannogo serdtsa.

In isolated hearts of cats and frogs, sistolic and diastolic pressure in the ventricle, volume speed, speed of contraction and relaxation, and indexes of contractability and elasticity, were estimated during stretching of the venous receptacle. The data showed that the stretching increased both the sistolic and diastolic activities of the ventricle. Shunting off of the intracardial nervous apparatus prevented these interrelationships. The increase in the ventricle sistolic and diastolic activities due to stimulation of mechanoreceptors of the heart venous receptacles can be regarded as the display of a regulatory activity of intracardial nervous system related to changes of the blood volume coming to the venous receptacles.

[Effect of electric stimulation rate on the indicators of systolic and diastolic activity of the left ventricle]. / Vliianie chastoty elektricheskoi stimuliatsii na pokazateli sistolicheskoi i diastolicheskoi aktivnosti levogo zheludochka.

The interrelationship of the indices of the systolic and diastolic myocardial activity with reference to the cardiac contractions rate was studied in acute experiments in isolated feline hearts. The study had demonstrated that moderate tachycardia (a 30% increase of the cardiac contractions rate) produced a beneficial inotropic effect, and increased the diastolic compliance of the myocardium. Severe tachycardia (a 80--100% increase of the contractions rate) produced a negative inotropic effect decreasing the myocardial compliance. Proceeding from the obtained results a conclusion is drawn that the cardiac contractions rate is an important factor in the regulation of not only the systolic, but also the diastolic myocardial activity.