[A difference in the growth-controlling action of Syrian hamster fibroblasts from early and late embryogenesis on tumor cells with different degrees of malignancy].

The difference in the effect of embryo fibroblasts from early (EHEF) and late (LHEF) embryos on the proliferative activity (PA) of transformed and tumour cells of different degree of malignancy was demonstrated in culture. The dense monolayer of EHEF cells exerted stronger growth-inhibitory influence on the PA of all tested strains of the transformed and tumour cells as compared to the LHEF cells.