Distribution of mitoses in mouse palatal epithelium.

Using colchicine as a stathmokinetic agent, regional variations in the distribution of dividing cells were investigated in the palatal epithelium of mice. The mitotic rate, estimated per unit length of epithelial surface or of epithelia/connective tissue (ECT) junction, was greater in the small rugae of the molar region than in the larger rugae behind the incisors. Immediately beneath the crest of each ruga, where tactile corpuscles are present and the epithelium is thin, mitoses were relatively sparse. A more regular distribution of mitoses was obtained if the mitotic index was based on unit length of ECT junction rather than on length of epithelial surface.