The effect of anti-promoters and calcium antagonists on V-79 Chinese hamster lung fibroblasts exposed to phorbol myristate acetate.

The effect of calcium antagonists and representative compounds from several classes of anti-promoters including anti-inflammatory sterols, protease inhibitors, retinoids and cyclic nucleotides on metabolic cooperation in cells treated with phorbol-12-myristate-13-acetate (PMA) was determined. Each compound was tested for its effect on metabolic cooperation and also for its ability to reverse or modify the inhibitory properties of PMA on intercellular communication at noncytotoxic exposure concentrations. Of all the compounds tested only cyclic AMP was able to antagonize the inhibitory effect of PMA. trans-Retinoic acid inhibited metabolic cooperation slightly at high exposure concentrations and acted synergistically with PMA to strongly inhibit intercellular communication in a dose-dependent manner.