Effect of unilateral vagotomy on capsaicin-induced neurogenic inflammation in the trachea of rats.

This study reports the effect of unilateral vagotomy on neurogenic inflammation in the trachea. Neurogenic inflammation was produced in the trachea of vagotomized rats by a venous injection of capsaicin, the pungent ingredient of red pepper. Monastral blue was used as tracer dye to label the affected blood vessels. Vagus nerves and tracheal tissues were processed for light and electron microscopy. The damaged right vagus nerve was found to have degenerated. However, unilateral vagotomy did not completely block neurogenic inflammation in the trachea ipsilaterally and contralaterally, as shown in the whole mount preparations. Microscopic observations of tracheal tissue sections showed that neurogenic inflammation did not evenly occur on both sides of the trachea. The possible reason for this is discussed.