The Clara cells activated by acetaminophen.

Many high mountaineers die of acute mountain sickness in the high mountains of Nepal during their adventure. Most of them administer acetaminophen (AP) as an analgesic. Various cells with higher expression of cytochrome P-450 (CYP) would metabolize AP and lead to cellular impairment. CYP is a major enzyme system in the metabolism of xenobiotics in different organs of the human being including in Clara cells of the lungs. Clara cells contain the highest concentration of CYP. We injected AP to C57BL/6J mice to examine the toxicity of AP in Clara cells. In 8 hours Clara cells show more prominent apical protrusion with edematous smooth endoplasmic reticulum (sER), reduced secretary granules, and edema. We speculate that using AP in a high mountain area might be harmful for Clara cells being a trigger of high altitude sickness.