Endocrinology, Vol 124, 233-239, Copyright © 1989 by Endocrine Society

ARTICLES

Divalent cations suppress 3',5'-adenosine monophosphate accumulation by stimulating a pertussis toxin-sensitive guanine nucleotide-binding protein in cultured bovine parathyroid cells

CJ Chen, JV Barnett, DA Congo and EM Brown
Endocrinology Division, Children's Hospital, Boston, Massachusetts 02115.

We used pertussis toxin to study the mechanism(s) by which divalent cations lower cellular cAMP content in bovine parathyroid cells. In cultured parathyroid cells, high extracellular Ca2+ (5 mM) or Mg2+ (5- 10 mM) lowers dopamine-stimulated cAMP content by 70-90%. Pertussis toxin (0.5 microgram/ml) totally blocks the inhibitory effects of Ca2+ and Mg2+ on cAMP content. Ba2+ and Sr2+ (5 mM) also lower cAMP content by 80-90%, and this effect is, likewise, blocked by pertussis toxin. Pretreatment with pertussis toxin had no effect on the release of cAMP into the extracellular fluid. The toxin also did not modify phosphodiesterase activity in sonicates of parathyroid cells (42.68 +/- 3.26 vs. 47.00 +/- 2.82 pmol cAMP hydrolyzed/10(6) cells.20 min in control and toxin-treated cells, respectively). Moreover, addition of the phosphodiesterase inhibitor isobutyl-methylxanthine did not modify the inhibition of dopamine-stimulated cAMP accumulation by 5 mM Ca2+ in control cells (85% vs. 86% inhibition, respectively, with and without isobutylmethylxanthine). Pertussis toxin-catalyzed ADP ribosylation in homogenates of control cells demonstrated the presence of two substrates with mol wt of 40K and 41K. Preexposure of cells to pertussis toxin overnight resulted in the complete loss of both substrates on subsequent ADP ribosylation with [32P]NAD. Pertussis toxin pretreatment did not enhance adenylate cyclase activity indirectly via reducing the extracellular Ca2+-induced rise in cytosolic Ca2+, since the cytosolic Ca2+ level at 5 mM Ca2+ was about 60% higher in pertussis toxin-treated than in control cells (531 +/- 85 vs. 326 +/- 35 nM; P less than 0.05). In addition, ionomycin had no significant effect on cellular cAMP levels in control cells despite increasing the cytosolic Ca2+ concentration to levels as high as 1700 nM at 10(-5) M. Thus, changes in cytosolic Ca2+ phosphodiesterase activity, or efflux of cAMP from the cell cannot explain the inhibition of cAMP accumulation by divalent cations or the reversal of this effect by pertussis toxin. Instead, the present data suggest that extracellular divalent cations modulate the formation of cellular cAMP in parathyroid cells by a process involving a pertussis toxin-sensitive guanine nucleotide regulatory protein, presumably inhibition of adenylate cyclase by Gi via a receptor-like mechanism.

This article has been cited by other articles:

				C. S Ritter, S. Pande, I. Krits, E. Slatopolsky, and A. J Brown Destabilization of parathyroid hormone mRNA by extracellular Ca2+ and the calcimimetic R-568 in parathyroid cells: role of cytosolic Ca and requirement for gene transcription J. Mol. Endocrinol., January 1, 2008; 40(1): 13 - 21. [Abstract] [Full Text] [PDF]

				N. Wettschureck, E. Lee, S. K. Libutti, S. Offermanns, P. G. Robey, and A. M. Spiegel Parathyroid-Specific Double Knockout of Gq and G11 {alpha}-Subunits Leads to a Phenotype Resembling Germline Knockout of the Extracellular Ca2+-Sensing Receptor Mol. Endocrinol., January 1, 2007; 21(1): 274 - 280. [Abstract] [Full Text] [PDF]

				J. Liao, A. Schneider, N. S. Datta, and L. K. McCauley Extracellular calcium as a candidate mediator of prostate cancer skeletal metastasis. Cancer Res., September 15, 2006; 66(18): 9065 - 9073. [Abstract] [Full Text] [PDF]

				E.F. NEMETH Misconceptions About Calcimimetics Ann. N.Y. Acad. Sci., April 1, 2006; 1068(1): 471 - 476. [Abstract] [Full Text] [PDF]

				A. Gerbino, W. C. Ruder, S. Curci, T. Pozzan, M. Zaccolo, and A. M. Hofer Termination of cAMP signals by Ca2+ and G{alpha}i via extracellular Ca2+ sensors: a link to intracellular Ca2+ oscillations J. Cell Biol., October 24, 2005; 171(2): 303 - 312. [Abstract] [Full Text] [PDF]

				N. Wettschureck and S. Offermanns Mammalian G Proteins and Their Cell Type Specific Functions Physiol Rev, October 1, 2005; 85(4): 1159 - 1204. [Abstract] [Full Text] [PDF]

				R. Caroppo, A. Gerbino, G. Fistetto, M. Colella, L. Debellis, A. M. Hofer, and S. Curci Extracellular calcium acts as a "third messenger" to regulate enzyme and alkaline secretion J. Cell Biol., July 5, 2004; 166(1): 111 - 119. [Abstract] [Full Text] [PDF]

				E. M. Brown and R. J. MacLeod Extracellular Calcium Sensing and Extracellular Calcium Signaling Physiol Rev, January 1, 2001; 81(1): 239 - 297. [Abstract] [Full Text] [PDF]

				N. Defer, M. Best-Belpomme, and J. Hanoune Tissue specificity and physiological relevance of various isoforms of adenylyl cyclase Am J Physiol Renal Physiol, September 1, 2000; 279(3): F400 - F416. [Abstract] [Full Text] [PDF]

				W. Chang, C. Tu, T.-H. Chen, L. Komuves, Y. Oda, S. A. Pratt, S. Miller, and D. Shoback Expression and Signal Transduction of Calcium-Sensing Receptors in Cartilage and Bone Endocrinology, December 1, 1999; 140(12): 5883 - 5893. [Abstract] [Full Text]

				B. W. Bapty, L.-J. Dai, G. Ritchie, L. Canaff, G. N. Hendy, and G. A. Quamme Mg2+/Ca2+ sensing inhibits hormone-stimulated Mg2+ uptake in mouse distal convoluted tubule cells Am J Physiol Renal Physiol, September 1, 1998; 275(3): F353 - F360. [Abstract] [Full Text] [PDF]

				M. C. d. J. Ferreira, C. Helies-Toussaint, M. Imbert-Teboul, C. Bailly, J.-M. Verbavatz, A.-C. Bellanger, and D. Chabardes Co-expression of a Ca2+-inhibitable Adenylyl Cyclase and of a Ca2+-sensing Receptor in the Cortical Thick Ascending Limb Cell of the Rat Kidney. INHIBITION OF HORMONE-DEPENDENT cAMP ACCUMULATION BY EXTRACELLULAR Ca2+ J. Biol. Chem., June 12, 1998; 273(24): 15192 - 15202. [Abstract] [Full Text] [PDF]

				E. F. Nemeth, M. E. Steffey, L. G. Hammerland, B. C. P. Hung, B. C. Van Wagenen, E. G. DelMar, and M. F. Balandrin Calcimimetics with potent and selective activity on the parathyroid calcium receptor PNAS, March 31, 1998; 95(7): 4040 - 4045. [Abstract] [Full Text] [PDF]

				S. E. McNeil, S. A. Hobson, V. Nipper, and K. D. Rodland Functional Calcium-sensing Receptors in Rat Fibroblasts Are Required for Activation of SRC Kinase and Mitogen-activated Protein Kinase in Response to Extracellular Calcium J. Biol. Chem., January 9, 1998; 273(2): 1114 - 1120. [Abstract] [Full Text] [PDF]

				M. L. Capece and R. Lydic cAMP and protein kinase A modulate cholinergic rapid eye movement sleep generation Am J Physiol Regulatory Integrative Comp Physiol, October 1, 1997; 273(4): R1430 - R1440. [Abstract] [Full Text] [PDF]

				M. Mailland, R. Waelchli, M. Ruat, H. G. W. M. Boddeke, and K. Seuwen Stimulation of Cell Proliferation by Calcium and a Calcimimetic Compound Endocrinology, September 1, 1997; 138(9): 3601 - 3605. [Abstract] [Full Text] [PDF]

				E. M. Brown, M. Pollak, C. E. Seidman, J.G. Seidman, Y.-H. W. Chou, D. Riccardi, and S. C. Hebert Calcium-Ion-Sensing Cell-Surface Receptors N. Engl. J. Med., July 27, 1995; 333(4): 234 - 240. [Full Text] [PDF]

				J. E. Garrett, I. V. Capuano, L. G. Hammerland, B. C. P. Hung, E. M. Brown, S. C. Hebert, E. F. Nemeth, and F. Fuller Molecular Cloning and Functional Expression of Human Parathyroid Calcium Receptor cDNAs J. Biol. Chem., May 26, 1995; 270(21): 12919 - 12925. [Abstract] [Full Text] [PDF]

				L. Canaff, J.-L. Petit, M. Kisiel, P. H. Watson, M. Gascon-Barre, and G. N. Hendy Extracellular Calcium-sensing Receptor Is Expressed in Rat Hepatocytes. COUPLING TO INTRACELLULAR CALCIUM MOBILIZATION AND STIMULATION OF BILE FLOW J. Biol. Chem., February 2, 2001; 276(6): 4070 - 4079. [Abstract] [Full Text] [PDF]