Circadian Rhythms in the Cell Division Rate of the Inner Enamel Epithelium and in the Uptake of 3H-Thymidine by the Root Tip of Rat Incisors

Abstract
There is a daily (circadian) fluctuation in the division rate of ameloblasts in the inner enamel epithelium of rat mandibular incisors ; a rhythm also exists in the uptake of injected 3H-thymidine by the root tip of the opposite incisor. The observed "nesting" phenomenon of mitotic figures is discussed.