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

Abstract Bone resorptive effects of prostaglandins (PGs) in cultured mandibular bone tissue of rat fetus prelabelled with 45 Ca were examined in comparison with those in radiusulna. PGE 1 , (3 × 10 −6 − 10 −4 M) and PGE 2 (3 × 10 −8 − 10 −4 M) could significantly stimulate the release of 45 Ca from mandible with a peak effect at 3 × 10 −6 M. The effects of PGEs were more marked in mandible than in radius-ulna. Salmon calcitonin (SCT) inhibited the stimulating effect of PGE 2 . PGF 2α did not cause the significant increase of 45 Ca-release. Parathyroid hormone (PTH) at concentrations of 0.01–1.0IU/ml dose-dependently stimulated 45 Ca-release and the effects were greater in mandible than in radius-ulna. Dibutyryl cyclic (DBc)-AMP stimulated the release of 45 Ca in mandible with a sharp peak effect at 5 × 10 −4 M. The results indicate that mandible is more susceptible to these bone resorptive agents than radius-ulna.