Autoradiographic study of colchicine inhibition of DNA synthesis and cell migration in hairless mouse epidermis in vivo.

In vivo effects of colchicine on mitotic counts, DNA synthesis, and cell migration time were investigated in hairless mouse epidermis. [H3]TdR was used to examine DNA synthesis and measure the transit time. We found that colchicine (at a dose of 50 micrograms/25 g body weight) caused mitotic arrest, but had no effect on the number of cells in S phase during the first 4 hr after injection. Colchicine reduced the number of cells in S phase in normal epidermis during the 16-30 hr after injection, but the effect was no longer seen at 42 hr post injection. A similar depression in S-phase cell counts appeared in UVR-stimulated hyperplastic epidermis by 48 hr after injection of colchicine. In addition, migration of [H3]TdR-labelled cells from the basal layer to the superficial layers in UVR-stimulated hyperplastic epidermis was disturbed by colchicine injection. The delay in movement was not seen during the first 24 hr, but appeared by 48 hr after injection.