[INFLUENCE OF NATURAL COMPOUNDS WITH POLYPHENOL STRUCTURE ON THE VASODILATION FUNCTION OF CEREBROVASCULAR ENDOTHELIUM...

It was studied the effect of two natural compounds with polyphenol structure, green tea polyphenols (Sigma-Aldrich) and catechol hydrate (Sigma-Aldrich) in a dose of 100 mg/kg, on the vasodilating function of endothelium in brain vessels of rats with model ischemic damage. The focal ischemia was modeled by occlusion of the right middle cerebral artery. The vasodilating function of endothelium was estimated from NO synthesis modification determined by means of the Doppler sonography technique. It was established that at the focal brain ischemia leads to the pronounced endothelial dysfunction that is confirmed by the suppressed reactivity of brain vessels to the action of a vasodilating factor (acetylcholine, Ach) and by development of the L-arginine paradox phenomenon. Upon the treatment with polyphenolic compounds studied, the ability of brain vessels to vasodilatation upon ACh introduction is retained. The observed blood flow enhancement (relative to negative control group) in response to the introduction of L-arginine significantly decreases upon the administration of green tea polyphenols and catechol hydrate (by a factor of 3.15 and 2.29, respectively). This result, in turn, gives grounds to assume that the polyphenolic compounds studied possess endothelium protecting properties.