Study of the immobilized subtilisins influence on coronary blood flow of an isolated rat heart

. In clinical medicine, some phenomenon has been noted: in many patients with anginal attacks during coronary angiography, significant obstructive processes in the coronary arteries are not detected. There is impaired coronary microcirculation due to dysfunction of endothelial and smooth muscle cells. This circumstance initiates the search for new drugs for pharmacological correction of the vasomotor status of coronary vessels in order to eliminate myocardial ischemia. Aim. To study the parameters of the coronary blood flow during the perfusion of an isolated heart with immobilized subtilisins (IS) in different dosages. Materials and methods. The effect of IS on coronary blood flow was studied using the Langendorff-perfused rat heart. The experiments were carried out on 50 male Wistar rats. Animals were divided into 5 groups: control (hearts perfused only with Krebs-Henseleit solution) and 4 experimental (1st — perfusion with IS at a concentration of 170 U/l; 2nd — perfusion with IS at a concentration of 340 U/l; 3rd — perfusion with IS at a concentration of 500 U/l; 4th — perfusion with IS at a concentration of 1000 U/l). Results. An increase in coronary blood flow was observed during perfusion with IS at concentrations of 170 and 340 U/l. With perfusion of IS at a concentration of 340 U/l, the vasodilating effect was significantly expressed. With perfusion at a concentration of 500 and 1000 U/l, a decrease in coronary flow was noted, which is most likely caused by vasoconstriction. Conclusion. When the heart is perfused with IS solution, the phenomenon of vasomotor activity of the coronary vessels is observed. The vasomotor effect caused by IS has a dose-dependent and multidirectional effect and is realized, most likely, through an allosteric effect on the natural mechanism of regulation of the coronary vessels tone.