Early stages in the development of goblet cells in the paranasal sinuses: a multimethodological study in the rabbit

To evaluate the pattern of goblet cell differentiation in sinus mucosa in response to external stimuli, New Zealand White rabbits were subjected to either experimental sinusitis or topical capsalcin application. Sinus mucosa was examined by light microscopy after serial sectioning, whole-mount preparation or immunohistochemistry. The mucosa was also examined by electron microscopy after perfusion fixation or high-pressure freezing. While goblet cells were normally very scarce in the healthy rabbit maxillary sinus mucosa, such cells were frequent after experimental sinusitis or topical capsaicin application. The process of goblet cell differentiation seems to follow a sequential path where serous secretory cells start to produce an increasing amount of mucous granules which appear electron lucent after conventional fixation. Parallel to this shift in secretion production, the cell assumes a bulging appearance after conventional fixation. It is concluded that newly formed goblet cells are recruited from intermediate secretory cell stages rather than from ciliated cells.