MORPHOLOGY OF A NAPHTHALENE-INDUCED BRONCHIOLAR LESION

Abstract

Nonciliated bronchiolar epithelial (Clara) [mouse] cells are selectively damaged by i.p. administration of naphthalene. These changes were examined using light microscopy, transmission electron microscopy, and scanning electron microscopy. Naphthalene administration causes the Clara cells to expand and exfoliate shortly thereafter. Following exfoliation the remaining ciliated cells show morphologic abnormalities, including cilia loss and ballooning of remaining cilia. Upon regeneration of the Clara cells the ciliated cells gradually return to their normal appearance. One possible explanation for these findings is that the Clara cell secretions directly affect the physiologic state of the surrounding ciliated cells.