The effects of drugs related to cyclic AMP and a tumor promoter, phorbol ester, on intercellular communications via gap junctions were investigated by the Lucifer Yellow-transfer method in cultured rabbit gastric epithelial cells. Cells were in contact with each drug for 4 hr before the microinjection of the dye into a cell. Dye transfer capacity was significantly increased by dibutyryl cyclic AMP (10-3 M), theophylline (10-3 M), 3-isobutyl-1-methylxanthine (10-4 M), forskolin (10-6 M) and irsogladine (10-4 M); and it was inhibited by 12-O-tetradecanoyl-phorbol-13-ac etate (100 ng/ml). These results suggest that the intercellular communication between cultured rabbit gastric epithelial cells is upregulated by cyclic AMP.

No abstract

No abstract

No abstract

No abstract