EFFECTS OF PARATHYROID-HORMONE, 1,25-DIHYDROXYVITAMIN D3, AND PROSTAGLANDIN-E2 ON ALKALINE-PHOSPHATASE ACTIVITY IN CULTURED DENTAL-PULP AND GINGIVA CELLS OF BOVINE CALF

The effects of parathyroid hormone (PTH), 1,25-dihydroxyvitamin D3, and prostaglandin E2 (PGE2) on alkaline phosphatase activity on cultured dental pulp and gingiva cells of bovine calf were compared. In pulp cells, PTH, 1,25-dihydroxyvitamin D3, and PGE2 significantly increased alkaline phosphatase activity, but no increase in the enzyme activity by these factors was observed in gingiva cells. Dibutyryl cAMP also increased alkaline phosphatase activity in both types of cell, but the increase in pulp cells was greater than that in gingiva cells. Treatment of the cultured pulp cells with PTH or PGE2 significantly increased the intracellular cAMP content. These results suggest that calciotropic factors such as PTH, 1,25-dihydroxyvitamin D3, and PGE2 may be involved in the differentiation of dental pulp cells and that some of these effects (those of PTH and PGE2) are mediated by cAMP.