Reversibility of the inhibitory effect of rhodamine B on the proliferation of cultured human lip fibroblasts.

ABSTRACT

To investigate the reversibility of rhodamine B inhibition of cell proliferation, human lip fibroblast KD cells were cultured for 3 days in the presence of 25 or 50 micrograms/ml of the dye and the effect of removal of the dye from the culture medium on cell histology and on incorporation of [3H]thymidine into the acid-insoluble fraction of the cell layer was investigated. Removal of rhodamine B on the last 1 or 2 days resulted in an increase in cell number, and incorporation of [3H]thymidine was also restored after removal of the dye; [3H]thymidine incorporation by the cells treated with the dye for only the 1st day was the same as that by the control cells cultured without the dye. In conclusion, it was shown that the decrease in KD cell proliferation caused by rhodamine B can be reversed by removal of the dye.