Circulatory changes in acute myocardial ischemia in dogs with experimental diabetes mellitus

: On alloxane-diabetic dogs under chloralose anaesthesia without opening the chest catheterization, extracorporal perfusion and resistography of coronary arteries, catheterization and continuous drainage of coronary sinus, catheterization of major vessels and heart chambers were performed. Acute myocardial ischemia was induced by the 60 s cessation of left circumflex coronary artery extracorporal perfusion. The magnitude and peculiarity of the systemic circulation reactions during acute myocardial ischemia in dogs with moderate and mild hyperglycemia (less than 12 mmol/l), didn't differ from those in control group. But the degrees of coronary arteries dilation in the ischemic area and coronary sinus blood oxygen saturation reduction were less and the velocity of the coronary arteries resistance recovery to the base level in reperfusion period was more in these animals than in healthy dogs. In severe alloxane diabetes (hyperglycemia more than 12 mmol/l), the reflectory components of circulation reactions during myocardial ischemia, namely heart contractility function decrease, bradycardia, peripheral vessels resistance and arterial blood pressure reduction, were weakened or even absent, but the recovery velocity of cardiohaemodynamic parameters and the level of metabolic processes in myocardium was significantly slowed in the reperfusion period.