Abstract
Patch clamp physiological techniques were used to characterize the voltage-activated calcium currents (VACC) expressed in the plasma membrane of osteoblastic cells as a function of time in culture and proliferative state of the cell. Osteoblast-enriched preparations were isolated by collagenase digestions of newborn rat calvaria and cultured under different conditions which affected cell proliferation (i.e., low serum in the media to arrest proliferation). VACC were isolated by replacing the intracellular potassium with cesium, and adding 1 μM tetrodotoxin to the bath. Under conditions that favored cell proliferation, low cell density, and media supplemented with 10% fetal calf serum (FCS), a transient calcium current was not expressed until day 3 in culture. There was a statistically significant relationship between the precentage of cells expressing this current and the time in culture. The magnitude of the current significantly increased as days in culture increased. Under the same conditions, the sustained VACC was detected after 7 or 8 days in culture. However, arresting cell proliferation after 2 days in culture by reducing the FCS concentration to 0.01% induced the expression of the sustained VACC the next day. The data suggest that the expression of VACC in the plasma membrane of rat calvarial osteoblasts depends on the time in culture and the state of proliferation of the cells. These results should prove to be valuable in studying the functional significance of VACC in osteoblastic cells and their regulation by various bone regulatory agents.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Yamaguchi D, Hahn T, Iida-Klein A, Kleeman C, Muallem S (1987) Parathyroid hormone-activated calcium channels in an osteoblast-like clonal osteosarcoma cell line. J Biol Chem 262: 7711–7718
Ren W, Tatakis D, Dziak R (1992) Effects of leukotrienes on osteoblastic cells: cytosolic calcium and cyclic AMP studies. In: Davidovitch Z (ed) The biological mechanisms of tooth movement and craniofacial adaptation. The Ohio State University Press, pp 375–384
Tatakis D, Dolce C, Dziak R (1989) Thrombin's effects on osteoblastic cells. I. Cytosolic calcium and phosphoinositides. Biochem Biophys Res Commun 164:119–127
Tsien R, Tsien R (1990) Calcium channels, stores, and oscillations. Ann Rev cell Biol 6:715–760
Yamaguchi D, Kleeman C, Muallem S (1987) Protein kinase C-activated calcium channel in the osteoblast-like clonal osteosarcoma cell line UMR-106. J Biol Chem 262:14967–14973
Caffrey J, Farach-Carson M (1989) Vitamin D3 metabolites modulate dihydropyridine sensitive calcium currents in clonal rat osteosarcoma cells. J Biol Chem 264:20265–20274
Amagai Y, Kasai S (1989) A voltage-dependent calcium current in mouse MC3T3-E1 osteogenic cells. Jpn J Physiol 39:773–777
Chesnoy-Marchais D, Fritsch J (1988) Voltage-gated sodium and calcium currents in rat osteoblasts. J Physiol 398:291–311
Duncan R, Misler S (1989) Voltage-activated and stretchactivated Ba+2 conducting channels in an osteoblast-like cell line (UMR 106). FEBS 251:17–21
Guggino S, Wagner J, Snowman A, Hester L, Sacktor B, Snyder S (1988) Phenylalkylamine-sensitive calcium channels in osteoblast-like osteosarcoma cells. J Biol Chem 263:10155–10161
Karpinsky E, Wu L, Civitelli R, Avioli L, Hruska K, Pang P (1989) Dihydropyridine-sensitive calcium channel in rodent osteoblastic cells. Calcif Tissue Int 45:54–57
Morain P, Peglion J, Giesen-Crouse E (1992) Ca+2 channel inhibition in a rat osteoblast-like cell line, UMR 106, by a new dihydropyridine derivative, S11568. Eur J Pharmacol 220:11–17
Cota G (1986) Calcium channel currents in pars intermedia cells of the rat pituitary gland. J Gen Physiol 88:83–105
Estacion M, Mordan L (1993) Expression of voltage-gated calcium channels correlates with PDGF-stimulated calcium influx and depends upon cell density in C3H 10T1/2 mouse fibroblasts. Cell Calcium 14:161–171
Lovinger D, White G (1989) Post-natal development of burst firing behavior and the low-threshold transient calcium current examined using freshly isolated neurons from rat dorsal root ganglia. Neurosci Lett 102:50–57
Luben R, Wong G, Cohn D (1976) Biochemical characterization with paratohormone and calcitonin of isolated bone cells: provisional identification of osteoclasts and osteoblasts. Endocrinology 99:526–534
Shlossmann M, Brown M, Shapiro E, Dziak R (1982) Calcitonin effects on isolated bone cells. Calcif Tissue Int 34:190–196
Hamill O, Marty A, Neher E, Sakmann B, Sigworth F (1981) Improved patch-clamp technique for high resolution current recordings from cells and cell-free membranes. Pflugers Arch 391:85–100
Hille B (1992) Chapter 1: Introduction. In: Ion channels of excitable membranes, 2nd ed. Sinauer Assoc. Inc., pp 1–20
Chen C, Corbley M, Roberts T, Hess P (1988) Voltage-sensitive calcium channels in normal and transformed 3T3 fibroblasts. Science 239:1024–1026
Cantiello H, Stow J, Prat A, Ausiello D (1991) Actin filaments regulate epithelial Na+ channels activity. Am J Physiol 261:C882–888
Guggino S, Lajeunesse D, Wagner J, Snyder S (1989) Bone remodeling signaled by a dihydropyridine- and phenylalkylamine-sensitive calcium channel. Proc Natl Acad Sci USA 86: 2957–2960
Ramsdell J (1991) Voltage-dependent calcium channels regulate GH4 pituitary cell proliferation at two stages of the cell cycle. J Cell Physiol 146:197–206
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Loza, J., Stephan, E., Dolce, C. et al. Calcium currents in osteoblastic cells: Dependence upon cellular growth stage. Calcif Tissue Int 55, 128–133 (1994). https://doi.org/10.1007/BF00297188
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00297188