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Endotoxemia induced by gram-negative bacteria leads to endotoxic shock pathogenetically stemming from the integral component of the bacterial wall--lipid A. The study made to define the ability of lipid A monoclonal antibodies to correct hemodynamic disturbances due to endotoxemia in dog experiments showed the efficacy of the antibodies administration. ReLPS isolated from Salmonella Minnesota was used as an antigen. Administration of the complex monoclonal antibodies-endotoxin caused no hemodynamic impairment.

The ultrasound contrast medium obtained by the original methods was administered into the left ventricular cavity and myocardium of 12 open-chest dogs by using a catheter. After its administration into the cavity there was its intensive contrast. When the ultrasound contrast was administered into the aortic root, the entire myocardium contrasted, on selective administrations of the contrast into the coronary arteries, the beds supplied by appropriate arteries contrasted. The ultrasound contrast study enabled the areas with impaired perfusion as echo-negative "filling defects" to be detected and mapped. The imaging of myocardial blood flow in tomographic sections and real time allows one to regard it promising for clinical use.

Operation for mammary-coronary shunting was reproduced on experimental dogs. Myocardial perfusion during shunting was accomplished through a shunt, passing in the mammary artery and introduced into the distal part of the coronary artery through an incision. This allowed the use of extracorporeal circulation and the development of myocardial ischemia to be avoided. The method makes it possible to create stenoses in any part of the vascular block. The authors analysed the dependence between the coronary blood flow and the pressure in the left ventricle and aorta by means of a mathematical model, which made it possible to separate the effect produced on the coronary blood flow by such parameters as the resistance and capacity of the large vessels, resistance of small vessels, pressure of arrest of the blood flow, and extravascular compression.

Mammary coronary bypass surgeries were performed in canine experiments. Myocardial perfusion was done via a shunt passing within the mammary artery and inserted into the distal portion of a coronary artery through a section, avoiding the application of extracorporeal circulation and myocardial ischemia. The method creates stenoses in any area of a vessel unit. A relationship was examined between coronary blood flow, left ventricular and aortic pressures by using a mathematical model that covers the effects of such parameters as resistance of great vessels, their capacity, minor vascular resistance, blood flow arrest and extravascular compression pressures on coronary blood flow.

Activated C protein (ACP) is a physiological anticoagulant enzyme that is capable to inactivate factors Va and VIIIa, thereby having a wide spectrum of antithrombotic effects. Low-dose ACP was tested for its ability to affect anodic current-induced arterial thrombosis in the rat. ACP given in low doses (15 micrograms/kg, 7% of total C protein in the rat) was found to produce a marked antithrombotic effect. With this, the activated partial thromboplastin time remained virtually unchanged, and its antithrombotic action was equal to that of heparin administered in a dose of 125 U/kg. In the authors' opinion, ACP may form the basis for designing a highly effective antithrombotic agent.

Left ventricle (LV) function and systemic hemodynamic changes after coronary artery embolization by 15 microns radioactive microspheres were studied in anesthetized rats. Selective coronary embolization was produced by microsphere injection during ascending aorta occlusion in closed chest animal by using "L"-shaped wire. Maximal pressure (Pmax) developed was evaluated during ascending aorta occlusion. Coronary embolization evoked dose-dependent reduction in Pmax and dP/dtmax and then decrease in basal LV systolic pressure. dP/dt/P, with parallel increase in end diastolic LV pressure. Changes of cardiac output were bidirectional: after administration of relatively small amount of microspheres cardiac output increased. This method can be used for producing quantitative myocardial ischemia and we suggest that it may be a suitable model of the chronic heart failure.

We analysed the relationship between artery pressure (AP) and coronary flow (F) in the canine coronary bed, using an electrical analog model of the coronary circulation. The model contained a capacitance of epicardial vessels, input and terminal resistances, diode, and the number of e.m.f., simulated the intramyocardial pressure and zero-flow pressure. These e.m.f. are assumed to be a linear functions of left ventricular and aortic pressure. The value of coronary blood flow was calculated from experimental curves of AP and LVP and setting parameters. Good agreement was obtained between theoretical and experimental curves of coronary blood flow.