An investigation of certain physiological mechanisms of the neurohumoral regulation of vascular tone.

The neuronal organization of the hypothalamobulbar system of regulation of vascular tone was studied in experiments on cats anesthetized with chloralose and nembutal and immobilized by dithylin [suxamethonium iodide]. It was established that the descending influence of the posterior, tuberal, and paraventricular structures of the hypothalamus on the activity of antidromically identified sympathicoactive reticulospinal neurons of the ventrolateral region of the medulla oblongata is realized by mono-, oligo-, and polysynaptic mechanisms. It was shown in a series of experiments carried out in rats that animals subjected to chemical desympathization, by contrast with the controls, do not develop chronic neurogenic hypertension during a six-week stressor influence on higher nervous activity. The central and peripheral neurohumoral mechanisms of the regulation of vascular tone are discussed.