EFFECT OF TETRAETHYLAMMONIUM ON THE TONE OF THE CORONARY ARTERIES UNDER BLOCKADE OF CONSTITUTIONAL AND INDUCIBLE NO-SYNTHASE BEFORE AND AFTER IMMOBILIZATION STRESS
The aim of the work was to determine the effect of tetraethylammonium on the volumetric flow rate of coronary flow, autoregulation index, maximum hyperemic flow, coronary reserve expansion and intensity of perfusion under the blockade of constitutional and inducible NO-synthase. The study showed that stress reduced the effect of tetraethylammonium on the tone of the coronary vessels. After stress with blockade of constitutive NO-synthase, the effect of tetraethylammonium on vascular tone is expressed at a greater extent than in the group of animals, undergoing stress with intact NO system, but still remained lower than in control. After immobilization with the blockade of inducible nitric oxide, influence of tetraethylammonium on vascular tone is restored to the values, detected in the hearts of the control animals not treated with blocker of nitric oxide synthesis. Thus, the post stress disorder of coronary tone mostly caused by inducible NO-synthase, generated in stress.