Summary
The present investigation was under-taken to determine if an interaction affecting45Ca release from prelabeled fetal rat long bones could be elicited by the Ca2+ ionophore, A-23187, and the phorbol ester, 12-myristate 13-acetate (PMA). Treatment with either A-23187 at a concentration of 0.3 μM or PMA at concentrations of 10−6 M, 10−7 M, and 10−8 M produced significant45Ca mobilization. When A-23187 and PMA were combined, enhanced45Ca release was observed on days 1 and 2 of culture. The stimulation of calcium mobilization noted on day 1 occurred when neither ionophore nor 10−6 M PMA treatments alone produced significant45Ca release. On day 2, cumulative45Ca release elicited by the combination of A-23187 plus 10−6 M PMA was slightly more than additive (15.9% for combination treatment vs. 13.7% for the sum of the individual treatments). Moreover, when A-23187 was combined with 10−7 M PMA on day 2, an enhancement of45Ca release was observed which was clearly more than additive (14.5% for combination treatment vs. 8.8% for the individual treatments), suggesting the possibility of a synergistic interaction between the two agents. These results were in marked contrast to those obtained with the inactive phorbol ester analog, phorbol 13-monoacetate. No stimulation of45Ca release was observed with 10−6 M and 10−7 M phorbol 13-monoacetate alone nor was enhanced45Ca release noted when the analog was combined with 0.3 μM A-23187. A synergistic enhancement of calcium mobilization by A-23187 and PMA could be indicative of mechanisms of bone resorption mediated by calcium-activated, calmodulin-dependent and C-kinase-dependent protein kinases.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Rasmussen H (1986) The calcium messenger system. I. N Engl J Med 314:1094–1101
Rasmussen H (1986) The calcium messenger system. II. N Engl J Med 314:1164–1170
Hokin LE (1985) Receptors and phosphoinositide-generated second messengers. Ann Rev Biochem 54:205–235
Vicentini LM, Villereal ML (1985) Activation of Na+/H+ exchange in cultured fibroblasts: synergism and antagonism between phorbol ester, Ca++ ionophore, and growth factors. Proc Natl Acad Sci USA 82:8053–8056
Halenda SP, Zavoico GB, Feinstein MB (1985) Phorbol esters and oleoyl acetoyl glycerol enhance release of arachidonic acid in platelets stimulated by Ca++ ionophore A-23187. J Biol Chem 260:12484–12491
Truneh A, Albert F, Golstein P, Schmitt-Verhulst A-M (1985) Early steps of lymphocyte activation bypassed by synergy between calcium ionophores and phorbol ester. Nature 313:318–320
Kaibuchi K, Takai Y, Sawamura M, Hoshijima M, Fujikura T, Nishizuka Y (1983) Synergistic functions of protein phosphorylation and calcium mobilization in platelet activation. J Biol Chem 258:6701–6704
Weiel JE, Adams DO, Hamilton TA (1985) Biochemical models of γ-interferon action: altered expression of transferrin receptors on murine peritoneal macrophages after treatment in vitro with PMA or A-23187. J Immunol 134:293–298
Hishikawa R, Fukase M, Yamatani T, Kadowaki S, Fujita T (1985) Phorbol ester stimulates calcitonin secretion synergistically with A-23187, and additively with dibutyryl cyclic AMP in rat c-cell line. Biochem Biophys Res Comm 132:424–429
Rappaport MS, Stern PH (1986) Parathyroid hormone and calcitonin modify inositol phospholipid metabolism in fetal rat limb bones. J Bone Min Res 1:173–179
Lorenzo JA, Raisz LG (1981) Divalent cation ionophores stimulate resorption and inhibit DNA synthesis in cultured fetal rat limb bone. Science 212:1157–1159
Dziak R, Stern PH (1975) Parathyromimetic effects of the ionophore, A-23187, on bone cells and organ cultures. Biochem Biophys Res Comm 65:1343–1349
Vargas SJ, Raisz LG (1986) Effects of pertussis toxin on stimulated and control resorption of fetal rat long bones. J Bone Min Res 1 (suppl 1, abstract 91)
Lorenzo J, Sousa S, Morrison N (1986) Phorbol esters stimulate resorption in fetal rat long bone cultures by a mechanism that is independent of prostaglandin synthesis. J Bone Min Res 1 (suppl 1, abstract 95)
Tashjian AH Jr, Ivey JL, Delclos B, Levine L (1978) Stimulation of prostaglandin production in bone by phorbol diesters and melittin. Prostaglandins 16:221–232
Ivey JL, Wright DR, Tashjian AH Jr (1976) Bone resorption in organ culture: inhibition by the divalent cation ionophores A-23187 and X-537A. J Clin Invest 58:1327–1338
Conaway HH, Diez LF, Raisz LG (1986) Effects of prostacyclin and prostaglandin E1 (PGE1) on bone resorption in the presence and absence of parathyroid hormone. Calcif Tissue Int 38:130–134
Steel RGD, Torrie JH (1970) Principles and procedures of statistics. McGraw-Hill, New York, p 99
Castagna M, Takai Y, Kaibuchi K, Sano K, Kikkawa U, Nishizuka Y (1982) Direct activation of calcium-activated phospholipid-dependent protein kinase by tumor-promoting phorbol esters. J Biol Chem 257:7847–7851
Stern PH (1985) Interactions of calcemic hormones and divalent cation ionophores on fetal rat bone in vitro. In: Rubin RP, Weiss GB, Putney JW (eds) Calcium in biological systems. Plenum Press, New York, London, p 541
Dziak R, Stern PH (1976) Responses of fetal rat bone organ cultures to the ionophore, A-23187. Calcif Tissue Res 22:137–147
May WS Jr, Sahyoun N, Wolf M, Cuatrecases P (1985) Role of intracellular calcium mobilization in the regulation of protein kinase C-mediated membrane processes. Nature 317:549–551
Wolf M, LeVine H III, May WS Jr, Cuatrecases P, Sahyoun N (1985) A model for intracellular translocation of protein kinase C involving synergism between Ca++ and phorbol esters. Nature 317:546–549
White JR, Huang C-K, Hill JM Jr, Naccache PH, Becker EL, Sha'afi RI (1984) Effect of phorbol 12-myristate 13-acetate and its analogue 4 α-phorbol 12, 13-didecanoate on protein phosphorylation and lysosomal enzyme release in rabbit neutrophils. J Biol Chem 259:8605–8611
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Abraham, D.C., Wadkins, C.L. & Conaway, H.H. Enhancement of fetal rat limb bone resorption by phorbol ester (PMA) and ionophore A-23187. Calcif Tissue Int 42, 191–195 (1988). https://doi.org/10.1007/BF02556333
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02556333