Lazuko S.S.
2-ethylthiobenzimidazol hydrobromide activates BКСa-channels of smooth muscle cells of rats’ aorta
Abstract.
The aim of this study was to show vasodilative effect of 2-ethylthiobenzimidazol hydrobromide, which is realized through the activation of calcium-activated potassium channels of high conductivity (ВKСa-channels) of smooth muscle cells of rats’ aorta.
The study was conducted on white non-linear female rats. Aortic rings with the width of 3 mm were excised from the middle third of the thoracic aorta and were placed in the thermostatic baths filled with Krebs-Henseleit solution, aerated with carbogen (95% O2 and 5% CO2) at the temperature of 37°С. The experiment was performed on the Schuler Organ bath Type 809 (Hugo Sachs Elektronik, Germany). The aortic rings were contracted in an isometric mode (force sensor F30 Type372 (Hugo Sachs Elektronik, Germany).
Dilatation was caused by increasing concentrations of 2-ethylthiobenzimidazol hydrobromide (from 10-15 to 10-3 M) or increasing concentrations of NS-1619 (from 10-10 to 10-3 M). Calcium-activated potassium channels of smooth muscle aortal cells were blocked by tetraethylammonium (TEA, 1 mM).
The fact that 2-ethylthiobenzimidazol hydrobromide affects the value of vasodilatation response of vessels through the activation of calcium-activated potassium channels of smooth muscle cells of arterial vessels to the same extent as an activator of ВКСа-channels NS-1619 was demonstrated in experiments on isolated aortal segments of rats.
The results, obtained in this study may be taken as the basis for proposals concerning the use of 2-ethylthiobenzimidazol hydrobromide as a vasoactive substance and also for those concerning the development of new drugs with the structure similar to bemytil, which are able to exert influence on the functional state of the endothelium and potassium channels of arterial vessels.
Key words: 2-ethylthiobenzimidazol hydrobromide, ВКCa-channels, vascular tone.
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