Rat osteogenic sarcoma cells: modulation of hormone stimulated cyclic AMP production by prostaglandin antagonists and biosynthesis inhibitors.

1. The effects of several anti-prostaglandin drugs on parathyroid hormone (PTH) and prostaglandin E2 (PGE2) stimulated cyclic AMP production in freshly isolated rat osteogenic sarcoma cells have been studied. 2. PG biosynthesis inhibitors (aspirin and indomethacin) did not inhibit the effect of PTH and arachidonic acid did not enhance PTH responsiveness. 3. The PG antagonists (SC-19220, phloretin phosphate polymers, 7-oxa-13-prostynoic acid) all inhibited PGE2-stimulated c-AMP production whilst only the phloretin phosphate polymers at high concentrations inhibited the PTH effect. 4. The data suggest that the primary action of PTH and PGE2 on these bone-derived cells is independent and that a PG is not involved in the initial event in PTH action.