Comparative Study of Immobilized Subtilisins and Nitroglycerin Influence on the Vasomotor Activity of the Rat Portal Vein

The drugs based on immobilized subtilisins have been created for direct plasmin-independent thrombolysis. At the same time, the effect of immobilized subtilisins on the vasomotor vascular activity hasn't been studied. It was performed a comparative study of the mutual competing influence of immobilized subtilisins and nitroglycerin on the vasomotor activity of an isolated rat vessel. The experiment was performed on 20 isolated fragments of the portal vein of Wistar rats. Two equal groups were formed in the experiment. In the first group, after a 20-minute stabilization period, the isolated vessel was perfused at first with a solution of nitroglycerin at the concentration of 11 mg/l, and then with a solution of immobilized subtilisins at the concentration of 340 U/l. In the second group, after a 20-minute stabilization period, the isolated vessel was perfused at first with a solution of immobilized subtilisins at the concentration of 340 U/l, and then with a solution of nitroglycerin at the concentration of 11 mg/l. The changes of the phasic motility of the rat portal vein in response to nitroglycerin perfusion were showed the negative inotropic and positive chronotropic effects, while the use of immobilized subtilisins was characterized by positive inotropic and negative chronotropic effects. At the same time, both drugs caused a decrease in the total tonic tension of the isolated portal vein. The established vasomotor effects of immobilized subtilisins are allowed to suggest the presence of specific receptors to them in the vascular wall.