Prostaglandin stimulation of adenosine 3′,5′-monophosphate accumulation in cultured chondrocytes in the presence or absence of parathyroid hormone

Abstract

The effect of prostaglandin analogues on the cycle AMP level in cultured chondrocytes were examined. Prostaglandin E 1 at 0.4 to 30 μM, increased the intracellular concentration of cyclic AMP in chondrocytes. Its effect was rapid, being evident within 1 min and reaching a maximum in 10 to 20 min. The maximum level was sustained until 30 min after its addition and then decreased gradually. Prostaglandin D 2 and E 2 also increased the cyclic AMP level in chondrocytes, but they had less effect than prostaglandin E 1. Prostaglandin A 1 had no effect on the nucleotide level in chondrocytes, although they markedly increased the level in fibroblasts. The time course of stimulation of cyclic AMP accumulation in chondrocytes by prostaglandin E 1, D 2 or E 2 was quite different from that by parathyroid hormone (PTH): the effect of prostaglandin was slower and more sustained than that of PTH. PTH potentiated the effect of prostaglandin E 1, E 2, or D 2 on the cyclic AMP level in chondrocytes and that the combined effects of prostaglandin, PTH or both produced a synergistic effect on the accumulation of cyclic AMP in the chondrocytes. These findings suggest that prostaglandin E 1, E 2, and D 2 increase the synthesis of cyclic AMP and that the combined effect of the prostaglandins and PTH on the cyclic AMP level in chondrocytes is partly attributed to the synergistic synthesis of cyclic AMP in the cells.