[Dynamics of changes in enterochromaffin cells during tumor growth]

A distinct correlation was found between changes in enterochromaffin cells producing highly active chemical substances--melatonin and serotonin, and stages of the neoplastic process. In early stages of tumor development a marked hyperplasia of enterochromaffin cells was noted, that was associated with enhancement of their histochemical properties. In advanced forms of cancer and chronic leucosis the number of cells is markedly reduced with simultaneous diminishing of their staining by specific histochemical methods. Such kinetics of changes of enterochromaffin cells appears to be related with definite antiblastic properties inherent to them and their products (melatonin and serotonin).