[Autoradiographic study of pigmented murine melanoma]

The growth of the Harding--Passey murine melanoma has been studied. The time of the tumor size doubling was found equal to 29, 45, 108 and 478 hours on days 8, 15, 22 and 30, resp., after melanoma transplantation. Factors determining the retardation of the melanoma growth rate were analysed. The cell cycle duration recorded on different days after the melanoma transplantation (15--30) was practically unchanged (18--21 hours). The value of the proliferative pool diminished from 71 to 51% on days 15 and 30, resp., after tumor transplantation. The cell loss sharply increased from 51 to 93% between 15 and 30 days of tumor growth. Thus, the retardation of the Harding-Passey melanoma growth was determined substantially by a markedly increased cell loss and, to some degree, by a decreased proliferative pool.