Labelled-calcium release from rat mandibles exposed to prostaglandins in vitro

Bone resorptive effects of prostaglandins (PGs) in cultured mandibular bone tissue of rat fetus prelabelled with 45Ca were examined in comparison with those in radius-ulna. PGE1 (3 X 10(-6)-10(-4) M) and PGE2 (3 X 10(-8)-10(-4) M) could significantly stimulate the release of 45Ca from mandible with a peak effect at 3 X 10(-6) M. The effects of PGEs were more marked in mandible than in radius-ulna. Salmon calcitonin (SCT) inhibited the stimulating effect of PGE2. PGF 2 alpha did not cause the significant increase of 45Ca-release. Parathyroid hormone (PTH) at concentrations of 0.01-1.0 IU/ml dose-dependently stimulated 45Ca-release and the effects were greater in mandible than in radius-ulna. Dibutyryl cyclic (DBc)-AMP stimulated the release of 45Ca in mandible with a sharp peak effect at 5 X 10(-4) M. The results indicate that mandible is more susceptible to these bone resorptive agents than radius-ulna.