AUTORADIOGRAPHIC STUDIES OF EXPERIMENTALLY INDUCED ATYPIAS IN THE CERVICAL EPITHELIUM OF MICE

The autoradiographic pattern of the cervix epithelium after iterated application of the carcinogen 3,4-benzpyrene was investigated in 100 C57B1 mice. There was a gradual increase in the proportion of labelled cells with increasing degree of atypias. Labelling of superficial layers occurred in almost all cases with severe atypias (grade III) and in 8 per cent of those with moderate atypias (grade II). The labelling of superficial cells in moderate atypias (grade II) suggests that, despite cytoplasmic maturation, their nuclei retained the property of less mature or of undifferentiated cells, i.e. the capacity to synthesize DNA. The highest number of labelled cells was found in mice presenting severe atypias with epithelial buds protruding into the stroma.