Abstract

The present experimental study on some basal neurophysiological systems aimed to evaluate the effect of the non-adrenergic non-cholinergic system on muscle contraction of the trachea and bronchi. Moreover, the study was targeted toward the investigation of the effect of the local intramural ganglion. The obtained results indicated that C-fibers, which represent the excitatory non-adrenergic non-cholinergic system, caused smooth muscle contraction by the realization of reflex through local intramural ganglia. Furthermore, it was observed that С-fibers affected the muscle by releasing tachykinins for constricting effect. The constricting influence of fibers was greater in the case of involving local reflex through the ganglion, and less significant in the case of activating of the humeral mechanism related to tachykinins. This finding became apparent as a result of the comparison of contractile muscle responses in Krebs-Henseleit's solution with atropine, and with activating C-fiber capsaicin applications. It was also observed that in the rat trachea and bronchus the elimination of NO-ergic mechanisms led to an increase in the contraction, and the dilatation effect of nitric oxide was associated with preganglionic and postganglionic nerve structures of the intramural ganglia. In conclusion, it is identified that afferent C-fibers increase the contractions of the smooth muscle of the trachea and bronchi of the rat mainly with the involvement of ganglion neurons. The humoral mechanism of C-fibers performs a minor and additional role in muscle contraction by the release of tachykinins. The obtained data can contribute to the study of the interaction of the autonomous nervous system and non-adrenergic non-cholinergic system.