[THE INFLUENCE OF HISTAMINE ON THE EFFECTOR NEURONS OF INTRAMURAL GANGLIA OF THE TRACHEA AND BRONCHI]

We considered the influence of the neurons of intramural ganglia in the reaction of the smooth muscle trachea and bronchi caused by electric field stimulation, by the action of histamine. We studied the effect of neurons of intramural ganglia in the activity of the smooth muscle trachea and bronchi in the action of low doses of histamine (0,1 and 10 μg/ml), L-NAME and hexamethonium. It was shown the blockade of neuronal transmission decreased the contraction of the smooth muscles trachea and bronchi by stimulation of the afferent nerve structures. The smooth muscle relaxation under the influence of hexamethonium was also reduced. Histamine and hexamethonium increased contractile activity and increased the amplitude of the relaxation of the trachea and bronchi. The inhibition of NO- synthesis did not affect on the contraction, but reduced the relaxation of the trachea and bronchi. Histamine and L-NAME enhanced contractile activity, but not modified smooth muscle relaxation. Concluded that the neurons of intramural ganglia have an inhibitory effect on the smooth muscle of the trachea and bronchi and may have a modulating effect on contraction and dilatation of the smooth muscles of the airways.