The regulatory effects of mesedin and beditin alpha2-adrenoblockers on the functional activity of the nervous, cardiovascular, and endocrine systems in rats under the hypoxic conditions.

One of the reasons of the development of pathologies causing death is hypoxia. The purposes of this study were (1) to study some physiological and biochemical mechanisms of α 2 -adrenoblockers, which ensure the tissue resistance increase to hypoxia; (2) to offer new drugs contributing to the increase of tissues' stability towards the hypoxic affection; and (3) to submit new medications to surpass by their anti-hypoxic activity of those already used in modern medicine and have some advantages. The reactivity of postsynaptic vascular α 2 -adrenoceptors was determined on the damaged spinal cord expressed by the blood pressure increase in response to intravenous administration of azepexole that selectively binds to α 2 -adrenoceptors. Determination of the systemic hemodynamic values and the vascular resistance to the blood flow was performed by the method with plastic microspheres of marked isotopes. pO 2 in the blood and the oxygen-transporting function were determined in a sample of 0.1 ml of blood in 30, 90, and 180 min after the α 2 -adrenoblockers' injections. It has been found that one of the major hemodynamic effects of mesedin and beditin was an improvement in cardiac output, as well as a prolonged increase in coronary blood flow and vasodilation of the heart vessels. Some anti-hypoxic mechanisms of the studied α 2 -adrenoblockers are an improvement of blood oxygen-transporting function followed by tissue oxygenation and the increased level of corticosterone and resistance to hypoxia. Revealing the mechanisms of action of the postsynaptic α 2 -adrenoceptors suggests that mesedin and beditin are potentially effective therapeutic means for many hypoxic conditions.