PARATHYROID-HORMONE (1-34) AND NLEU8,18TYR34-PARATHYROID HORMONE, (3-34) AMIDE INCREASE DIACYLGLYCEROL IN NEONATAL MOUSE CALVARIA

Previously, we and others have presented evidence that a calcium second messenger system is involved in the action of parathyroid hormone (PTH) on bone. In the present report, the effects of PTH(1-34) and PTH(3-34) amide treatment on diacylglycerol (DG) in neonatal mouse calvaria are described. PTH(1-34) produced a rapid (within 5 minutes) increase in calvarial incorporation of H-3-arachidonic acid into DG. The effect was maximal at 0.1 nMPTH(1-34), the lowest concentration tested. The 3-34 amide analogue of PTH increased DG to the same extent as PTH(1-34). The effect was maximal at 10 nM PTH(3-34) amide, the lowest concentration tested. These concentrations were lower than those required to elicit maximal effects on bone resorption. In contrast to effects on cyclic AMP. where the 3-34 amide inhibited the increase elicited by PTH, combined treatment of calvaria with PTH(1-34) and PTH(3-34)amide did not inhibit effects on resorption or diacylglycerol.