MWCNT causes extensive damage to the ciliated epithelium of the trachea of rodents.

The ciliated tracheobronchial epithelium plays an important role in the excretion of inhaled dust. While many reports indicate that inhaled multi-walled carbon nanotubes (MWCNT) induce inflammation and proliferative changes in the lung and pleura, their effects on the upper airway have not been reported. Two different types of MWCNTs, MWCNT-L (8 µm in length and 150 nm in diameter) and MWCNT-S (3 µm in length and 15 nm in diameter), were examined for their effect on the trachea as well as the bronchus and lung.

Enhancement of Ca(2+) influx and ciliary beating by membrane hyperpolarization due to ATP-sensitive K(+) channel opening in mouse airway epithelial cells.

Among the several types of cells composing the airway epithelium, the ciliary cells are responsible for one of the most important defense mechanisms of the airway epithelium: the transport of inhaled particles back up into the throat by coordinated ciliary movement. Changes in the cytoplasmic Ca(2+) concentration ([Ca(2+)]i) are the main driving force controlling the ciliary activity. In mouse ciliary cells, membrane hyperpolarization from -20 to -60 mV under whole-cell voltage-clamp induced a slow but significant [Ca(2+)]i rise in a reversible manner.