[DNA distribution and mitotic index in Ehrlich ascites tumor after colchicine administration]

Additional information like the type of growth is efficient for the interpretation of single parameter DNA distribution curves of tumors. The consideration of mitotic indices leads to further insights. The different growth phases of the Ehrlich ascites tumor are characterized by reproducible DNA histograms. The mitotic index and the frequency of the four mitotic phases turn out to be independent of the growth phase. Colchicine exerts an obvious effect on the prophases and metaphases. In the histogram an accumulation of cells in the G2M phase is evident, also on a higher ploidy level. Nearly identical DNA histograms result in different growth phases. The mitotic index of prophases and metaphases is found to be nearly twice at the 11th and 15th day of growth in comparison with the 8th day. This indicates a higher sensitivity of the Ehrlich ascites tumor to colchicine in steady state which is not expressed in the histogram.