ROLE OF CYTOPLASMIC MEMBRANE IN THE SCREENING OF POTENTIAL TUMOR PROMOTERS

The functional changes of cytoplasmic membrane of mammalian cells as a n alternative approach for evaluating the tumor promoter activity were investigated. The V79 metabolic cooperation assay, as the standard me thod for detection of tumor promoters in vitro was used, From three kn own tumor promoters only phenobarbital increased the efflux of [H-3]2- deoxy-D-glucose-6-phosphate from the cells in the same concentration r ange where the inhibition of metabolic cooperation was estimated. Neit her TPA, saccharin nor theophylline caused any functional changes of c ytoplasmic membrane of V79 cells. On the basis of the results with kno wn tumor promoters we suggest that following the functional changes of cytoplasmic membrane is not a convenient approach for screening poten tial tumor promoters.