INHIBITORY EFFECT OF DIBUTYRYL CYCLIC AMP ON THE RELEASE OF CALCIUM, INORGANIC PHOSPHATE AND LYSOSOMAL ENZYMES FROM CALVARIAL BONES CULTURED FOR 24 HOURS

Abstract

The effect of dibutyryl cyclic (dbc)AMP on the mobilization of Ca2+, Pi and lysosomal enzymes was studied in a bone culture system for 24 h using half calvaria from 6-7 day old mice. DbcAMP inhibited spontaneous and parathyroid hormone-stimulated mineral mobilization. DbcAMP in a concentration of 5 .times. 10-4M reduced the activities of .beta.-glucuronidase, .beta.-galactosidase and acid phosphatase found in the media; the activities of lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase were not affected. cAMP is not a stimulator but an inhibitor, of bone resorption within the culture period. The cyclid nucleotide might interfere with release processes involved in bone resorption.