[Clinical features of neurohumoral regulation of the vascular tonus in patients with recurrent nasal bleedings].

Norepinephrine (NE), dopamine, histamine and serotonin levels in the blood were measured fluorometrically in 54 patients with nasal bleedings (NB) aged 15 to 23 years. Of them, 18 patients suffered from habitual NB, 36 had NB because of hypertension. Biogenic amines were studied before and after graded exercise (GE). Low basal levels of serotonin, NE and dopamine were found in all the examinees. Patients with habitual NB had also high basal level of histamine. Such correlation of biogenic amines points to abnormal relations between vasoconstrictive and vasodilating mechanisms of neurohumoral vascular regulation disturbing microcirculation in nasal mucosa, suppresses tonicity of the capacitive vessels, leads to their overfilling, progression of circulatory hypoxia and metabolic acidosis, makes bleedings recurrent. Similarity of neurohumoral adaptation reactions to GE in patients with habitual and hypertensive NB suggests the presence of the same mechanisms of NB onset and their recurrences in various primary causes.