[Significance of tissue specificity for the frequency of mitosis and it's changes (author's transl)].

A 15 fold increase in the rate of mitosis was found in the lower third of the crypts of Lieberkühn in the duodenum of albino rats which had received a dose of colchicine or colchicine after a long treatment with glibenclamid compared with untreated rats. The B-cells of the islets of Langerhans of all rats in the colchicine + glibenclamid group showed however an 18 fold increase in the rate of mitosis in relation to the other two groups. The high number of cells found in the mitotic state in the duodenum of the colchicine treated rats is due to the prevention of further differentiation and hinderance of locomotion of the already high number of cells undergoing mitosis. The B-cells appear to be insensitive to colchicine, probably because they divide only occasionally and tend to remain in the same place, but they are shown to be sensitive to glibenclamid. It is concluded that the influence of external factors on the frequency of mitosis depends primarily on the particular characteristics of the tissue.