Effects of steroid hormones on the multiplication of cells

Abstract

Since the action of hormones in the tissue is complicatedly related or combined, the pure action of steroid hormones is rarely investgated in vivo. The purpose of the present examinations was to determine the direct effects of steroid hormones on the multiplication of the following cells : Fibroblasts from chick embryo hearts, MK cells, PS cells, FL cells, HeLa cells and AH-130 cells. In order to determine accurately the effects, the tissue culture method was employed and a large quantity of the hormones was added in the medium.1) In 7 days' cultivation, paramethasone showed an inhibitory effect on the multiplication of Fibroblasts from chick embryo hearts proportional to the increase of concentration. Paramethasone in the concentration of 6.6 pg/cc had a 30% inhibitory effect in comparison with the control culture. In the concentration of 6.6 and 33.3μtg/cc, 4-chlorotestosterone acetate gave little effect on the multiplication of Fibroblasts, almost similar to the control culture, but in the concentration of 66.6 μg/cc, it gave slight inhibitory effects.2) The multiplication of MK cells and PS cells was inhibited by paramethasone in proportion to the increase of concentration : 6.6, 33.3 and 66.6 pg/cc of culture medium, respectively. The inhibitory effects were marked in the case of MK cells.3) The multiplication of strain FL cells was makedly inhibited by the addition of 66.6, ag/cc paramethasone, and paramethasone in the concentration of 6.6 μg/cc showed 46% inhibitory effect after 7 days' cultivation.Strain HeLa cells were much more sensitive to paramethasone than strain FL cells, namely, 33.3 μg/cc paramethasone showed 80% inhibitory effect in comparison with the control culture ; 4-chlorotestosterone acetate showed lower inhibitory effect than paramethasone in each concentration : 6.6, 33.3 and 66.6 μg/cc, respectively on the 7th day of cultivation.4) The inhibitory effects of adrenocorticosteroids on chick embryo pulmonary tissues and FL cells were reversible in a concentration lower than 100 μg per cc.Paramethasone in the concentration of 66.6 μg/cc had a marked inhibitory effect on the multiplication of FL cells tested, but cell growth was evident after removing paramethasone and thoroughly washing the culture with PBS solution, then adding YLE medium.5) On examination, the mixture of paramethasone and 4-chlorotestosterone acetate in the concentration of 10μg/cc a slight antagonistic effect was observed. When paramethasone was added alone to the medium, it gave a 50% inhibitory effect on the multiplication of FL cells. In the culture which 10μg/cc paramethasone and 4-chlorotestosterone acetate were added, the inhibitory effect was reduced to 38%.6) Paramethasone-treated FL cells became round in shape and tended to cohere themselves in sheets in which a great number of giant cells were often seen. These morphologic changes were also seen in high concentration of paramethasone, and FL cells turned into spindle-shaped ones in the concentration of 100 μg/cc.The nuclei of typical accites hepatoma 130 cells were of various sizes and irregularly shaped. To the contrary, when these cells were treated with paramethasone, they had small and nearly round nuclei in proportion to the increasing concentration, and the cytoplasm contained many vacuoles.7) In the concentration 50 /2g/cc paramethasone, the mitotic coefficiency decreased to two-thirds of control values in FL cells, five-eighths in MK cells, one-third in AH-130 cells. In 4-chlorotestosterone acetate-treated FL cells, it slightly increased.8) Prednisolone in the concentration of 10 μg/cc produced a delay and partial inhibition of cytopathic effect when introduced into HeLa cell cultures at the time of infection with HV J. The titer of virus as measured by hemagglutination was dereased slightly in prednisolone-treated groups after 72 hours of incubation.