Skip to main content
PMC home page
The EMBO Journal logoLink to The EMBO Journal
. 1995 Mar 15;14(6):1075–1083. doi: 10.1002/j.1460-2075.1995.tb07090.x

Stimulation of single L-type calcium channels in rat pituitary GH3 cells by thyrotropin-releasing hormone.

M Mantegazza 1, C Fasolato 1, J Hescheler 1, D Pietrobon 1
PMCID: PMC398184  PMID: 7720698

Abstract

Hormonal stimulation of voltage-dependent Ca2+ channels in pituitary cells is thought to contribute to the sustained phase of Ca2+ entry and secretion induced by secretion stimulating hormones and has been suggested as a mechanism for refilling the Ca2+ stores. Using the cell-attached patch-clamp technique, we studied the stimulation of single Ca2+ channels by thyrotropin-releasing hormone (TRH) in rat GH3 cells. We show that TRH applied from the bath switched the activity of single L-type Ca2+ channels from a gating mode with very low open probability (po) to a gating mode with slightly smaller conductance but 10 times higher po. Interconversions between these two gating modes were also observed under basal conditions, where the equilibrium was shifted towards the low po mode. TRH applied from the pipette had no effect, indicating the involvement of a cytosolic compound in the stimulatory pathway. We show that TRH does not potentiate all the L-type Ca2+ channels in a given membrane patch and report evidence for co-expression of two functionally different L-type Ca2+ channels. Our results uncover the biophysical mechanism of hormonal stimulation of voltage-dependent Ca2+ channels in GH3 cells and are consistent with differential modulation of different subtypes of dihydropyridine-sensitive Ca2+ channels.

Full text

PDF
1076

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Artalejo C. R., Ariano M. A., Perlman R. L., Fox A. P. Activation of facilitation calcium channels in chromaffin cells by D1 dopamine receptors through a cAMP/protein kinase A-dependent mechanism. Nature. 1990 Nov 15;348(6298):239–242. doi: 10.1038/348239a0. [DOI] [PubMed] [Google Scholar]
  2. Baron A., Loirand G., Pacaud P., Mironneau C., Mironneau J. Dual effect of thrombin on voltage-dependent Ca2+ channels of portal vein smooth muscle cells. Circ Res. 1993 Jun;72(6):1317–1325. doi: 10.1161/01.res.72.6.1317. [DOI] [PubMed] [Google Scholar]
  3. Bean B. P. Neurotransmitter inhibition of neuronal calcium currents by changes in channel voltage dependence. Nature. 1989 Jul 13;340(6229):153–156. doi: 10.1038/340153a0. [DOI] [PubMed] [Google Scholar]
  4. Benham C. D. Voltage-gated and agonist-mediated rises in intracellular Ca2+ in rat clonal pituitary cells (GH3) held under voltage clamp. J Physiol. 1989 Aug;415:143–158. doi: 10.1113/jphysiol.1989.sp017716. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Bernheim L., Beech D. J., Hille B. A diffusible second messenger mediates one of the pathways coupling receptors to calcium channels in rat sympathetic neurons. Neuron. 1991 Jun;6(6):859–867. doi: 10.1016/0896-6273(91)90226-p. [DOI] [PubMed] [Google Scholar]
  6. Bonev A., Isenberg G. Arginine-vasopressin induces mode-2 gating in L-type Ca2+ channels (smooth muscle cells of the urinary bladder of the guinea-pig). Pflugers Arch. 1992 Feb;420(2):219–222. doi: 10.1007/BF00374994. [DOI] [PubMed] [Google Scholar]
  7. Brown A. M., Birnbaumer L. Ionic channels and their regulation by G protein subunits. Annu Rev Physiol. 1990;52:197–213. doi: 10.1146/annurev.ph.52.030190.001213. [DOI] [PubMed] [Google Scholar]
  8. Cavalié A., Allen T. J., Trautwein W. Role of the GTP-binding protein Gs in the beta-adrenergic modulation of cardiac Ca channels. Pflugers Arch. 1991 Nov;419(5):433–443. doi: 10.1007/BF00370785. [DOI] [PubMed] [Google Scholar]
  9. Chin H., Smith M. A., Kim H. L., Kim H. Expression of dihydropyridine-sensitive brain calcium channels in the rat central nervous system. FEBS Lett. 1992 Mar 24;299(1):69–74. doi: 10.1016/0014-5793(92)80103-n. [DOI] [PubMed] [Google Scholar]
  10. Clapham D. E. Direct G protein activation of ion channels? Annu Rev Neurosci. 1994;17:441–464. doi: 10.1146/annurev.ne.17.030194.002301. [DOI] [PubMed] [Google Scholar]
  11. Clapham D. E., Neer E. J. New roles for G-protein beta gamma-dimers in transmembrane signalling. Nature. 1993 Sep 30;365(6445):403–406. doi: 10.1038/365403a0. [DOI] [PubMed] [Google Scholar]
  12. Cohen C. J., McCarthy R. T., Barrett P. Q., Rasmussen H. Ca channels in adrenal glomerulosa cells: K+ and angiotensin II increase T-type Ca channel current. Proc Natl Acad Sci U S A. 1988 Apr;85(7):2412–2416. doi: 10.1073/pnas.85.7.2412. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Delcour A. H., Lipscombe D., Tsien R. W. Multiple modes of N-type calcium channel activity distinguished by differences in gating kinetics. J Neurosci. 1993 Jan;13(1):181–194. doi: 10.1523/JNEUROSCI.13-01-00181.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Delcour A. H., Tsien R. W. Altered prevalence of gating modes in neurotransmitter inhibition of N-type calcium channels. Science. 1993 Feb 12;259(5097):980–984. doi: 10.1126/science.8094902. [DOI] [PubMed] [Google Scholar]
  15. Ellinor P. T., Zhang J. F., Randall A. D., Zhou M., Schwarz T. L., Tsien R. W., Horne W. A. Functional expression of a rapidly inactivating neuronal calcium channel. Nature. 1993 Jun 3;363(6428):455–458. doi: 10.1038/363455a0. [DOI] [PubMed] [Google Scholar]
  16. Forscher P., Oxford G. S., Schulz D. Noradrenaline modulates calcium channels in avian dorsal root ganglion cells through tight receptor-channel coupling. J Physiol. 1986 Oct;379:131–144. doi: 10.1113/jphysiol.1986.sp016244. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Forti L., Pietrobon D. Functional diversity of L-type calcium channels in rat cerebellar neurons. Neuron. 1993 Mar;10(3):437–450. doi: 10.1016/0896-6273(93)90332-l. [DOI] [PubMed] [Google Scholar]
  18. Gandevia S. C., Killian K., McKenzie D. K., Crawford M., Allen G. M., Gorman R. B., Hales J. P. Respiratory sensations, cardiovascular control, kinaesthesia and transcranial stimulation during paralysis in humans. J Physiol. 1993 Oct;470:85–107. doi: 10.1113/jphysiol.1993.sp019849. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Gollasch M., Haller H., Schultz G., Hescheler J. Thyrotropin-releasing hormone induces opposite effects on Ca2+ channel currents in pituitary cells by two pathways. Proc Natl Acad Sci U S A. 1991 Nov 15;88(22):10262–10266. doi: 10.1073/pnas.88.22.10262. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Gollasch M., Kleuss C., Hescheler J., Wittig B., Schultz G. Gi2 and protein kinase C are required for thyrotropin-releasing hormone-induced stimulation of voltage-dependent Ca2+ channels in rat pituitary GH3 cells. Proc Natl Acad Sci U S A. 1993 Jul 1;90(13):6265–6269. doi: 10.1073/pnas.90.13.6265. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Hamill O. P., Marty A., Neher E., Sakmann B., Sigworth F. J. Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pflugers Arch. 1981 Aug;391(2):85–100. doi: 10.1007/BF00656997. [DOI] [PubMed] [Google Scholar]
  22. Herzig S., Patil P., Neumann J., Staschen C. M., Yue D. T. Mechanisms of beta-adrenergic stimulation of cardiac Ca2+ channels revealed by discrete-time Markov analysis of slow gating. Biophys J. 1993 Oct;65(4):1599–1612. doi: 10.1016/S0006-3495(93)81199-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Hescheler J., Rosenthal W., Hinsch K. D., Wulfern M., Trautwein W., Schultz G. Angiotensin II-induced stimulation of voltage-dependent Ca2+ currents in an adrenal cortical cell line. EMBO J. 1988 Mar;7(3):619–624. doi: 10.1002/j.1460-2075.1988.tb02855.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Hess P., Lansman J. B., Tsien R. W. Different modes of Ca channel gating behaviour favoured by dihydropyridine Ca agonists and antagonists. Nature. 1984 Oct 11;311(5986):538–544. doi: 10.1038/311538a0. [DOI] [PubMed] [Google Scholar]
  25. Hille B. G protein-coupled mechanisms and nervous signaling. Neuron. 1992 Aug;9(2):187–195. doi: 10.1016/0896-6273(92)90158-a. [DOI] [PubMed] [Google Scholar]
  26. Horn R., Lange K. Estimating kinetic constants from single channel data. Biophys J. 1983 Aug;43(2):207–223. doi: 10.1016/S0006-3495(83)84341-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Hui A., Ellinor P. T., Krizanova O., Wang J. J., Diebold R. J., Schwartz A. Molecular cloning of multiple subtypes of a novel rat brain isoform of the alpha 1 subunit of the voltage-dependent calcium channel. Neuron. 1991 Jul;7(1):35–44. doi: 10.1016/0896-6273(91)90072-8. [DOI] [PubMed] [Google Scholar]
  28. Hullin R., Singer-Lahat D., Freichel M., Biel M., Dascal N., Hofmann F., Flockerzi V. Calcium channel beta subunit heterogeneity: functional expression of cloned cDNA from heart, aorta and brain. EMBO J. 1992 Mar;11(3):885–890. doi: 10.1002/j.1460-2075.1992.tb05126.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Kamishima T., Nelson M. T., Patlak J. B. Carbachol modulates voltage sensitivity of calcium channels in bronchial smooth muscle of rats. Am J Physiol. 1992 Jul;263(1 Pt 1):C69–C77. doi: 10.1152/ajpcell.1992.263.1.C69. [DOI] [PubMed] [Google Scholar]
  30. Keja J. A., Kits K. S. Single-channel properties of high- and low-voltage-activated calcium channels in rat pituitary melanotropic cells. J Neurophysiol. 1994 Mar;71(3):840–855. doi: 10.1152/jn.1994.71.3.840. [DOI] [PubMed] [Google Scholar]
  31. Kramer R. H., Kaczmarek L. K., Levitan E. S. Neuropeptide inhibition of voltage-gated calcium channels mediated by mobilization of intracellular calcium. Neuron. 1991 Apr;6(4):557–563. doi: 10.1016/0896-6273(91)90058-8. [DOI] [PubMed] [Google Scholar]
  32. Lipscombe D., Kongsamut S., Tsien R. W. Alpha-adrenergic inhibition of sympathetic neurotransmitter release mediated by modulation of N-type calcium-channel gating. Nature. 1989 Aug 24;340(6235):639–642. doi: 10.1038/340639a0. [DOI] [PubMed] [Google Scholar]
  33. Loirand G., Pacaud P., Mironneau C., Mironneau J. GTP-binding proteins mediate noradrenaline effects on calcium and chloride currents in rat portal vein myocytes. J Physiol. 1990 Sep;428:517–529. doi: 10.1113/jphysiol.1990.sp018225. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Marrion N. V. Selective reduction of one mode of M-channel gating by muscarine in sympathetic neurons. Neuron. 1993 Jul;11(1):77–84. doi: 10.1016/0896-6273(93)90272-s. [DOI] [PubMed] [Google Scholar]
  35. McManus O. B., Blatz A. L., Magleby K. L. Sampling, log binning, fitting, and plotting durations of open and shut intervals from single channels and the effects of noise. Pflugers Arch. 1987 Nov;410(4-5):530–553. doi: 10.1007/BF00586537. [DOI] [PubMed] [Google Scholar]
  36. Mollard P., Vacher P., Rogawski M. A., Dufy B. Vasopressin enhances a calcium current in human ACTH-secreting pituitary adenoma cells. FASEB J. 1988 Oct;2(13):2907–2912. doi: 10.1096/fasebj.2.13.2844618. [DOI] [PubMed] [Google Scholar]
  37. Nelson M. T., Standen N. B., Brayden J. E., Worley J. F., 3rd Noradrenaline contracts arteries by activating voltage-dependent calcium channels. Nature. 1988 Nov 24;336(6197):382–385. doi: 10.1038/336382a0. [DOI] [PubMed] [Google Scholar]
  38. Neveu D., Nargeot J., Richard S. Two high-voltage-activated, dihydropyridine-sensitive Ca2+ channel currents with distinct electrophysiological and pharmacological properties in cultured rat aortic myocytes. Pflugers Arch. 1993 Jun;424(1):45–53. doi: 10.1007/BF00375101. [DOI] [PubMed] [Google Scholar]
  39. Ochi R., Kawashima Y. Modulation of slow gating process of calcium channels by isoprenaline in guinea-pig ventricular cells. J Physiol. 1990 May;424:187–204. doi: 10.1113/jphysiol.1990.sp018062. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Ozawa S., Sand O. Electrophysiology of excitable endocrine cells. Physiol Rev. 1986 Oct;66(4):887–952. doi: 10.1152/physrev.1986.66.4.887. [DOI] [PubMed] [Google Scholar]
  41. Perez-Reyes E., Castellano A., Kim H. S., Bertrand P., Baggstrom E., Lacerda A. E., Wei X. Y., Birnbaumer L. Cloning and expression of a cardiac/brain beta subunit of the L-type calcium channel. J Biol Chem. 1992 Jan 25;267(3):1792–1797. [PubMed] [Google Scholar]
  42. Pietrobon D., Hess P. Novel mechanism of voltage-dependent gating in L-type calcium channels. Nature. 1990 Aug 16;346(6285):651–655. doi: 10.1038/346651a0. [DOI] [PubMed] [Google Scholar]
  43. Rittenhouse A. R., Hess P. Microscopic heterogeneity in unitary N-type calcium currents in rat sympathetic neurons. J Physiol. 1994 Jan 1;474(1):87–99. doi: 10.1113/jphysiol.1994.sp020005. [DOI] [PMC free article] [PubMed] [Google Scholar]
  44. Rosenthal W., Hescheler J., Hinsch K. D., Spicher K., Trautwein W., Schultz G. Cyclic AMP-independent, dual regulation of voltage-dependent Ca2+ currents by LHRH and somatostatin in a pituitary cell line. EMBO J. 1988 Jun;7(6):1627–1633. doi: 10.1002/j.1460-2075.1988.tb02989.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Schlegel W., Winiger B. P., Mollard P., Vacher P., Wuarin F., Zahnd G. R., Wollheim C. B., Dufy B. Oscillations of cytosolic Ca2+ in pituitary cells due to action potentials. Nature. 1987 Oct 22;329(6141):719–721. doi: 10.1038/329719a0. [DOI] [PubMed] [Google Scholar]
  46. Sigworth F. J., Sine S. M. Data transformations for improved display and fitting of single-channel dwell time histograms. Biophys J. 1987 Dec;52(6):1047–1054. doi: 10.1016/S0006-3495(87)83298-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  47. Snutch T. P., Tomlinson W. J., Leonard J. P., Gilbert M. M. Distinct calcium channels are generated by alternative splicing and are differentially expressed in the mammalian CNS. Neuron. 1991 Jul;7(1):45–57. doi: 10.1016/0896-6273(91)90073-9. [DOI] [PubMed] [Google Scholar]
  48. Spiegel A. M. G proteins in cellular control. Curr Opin Cell Biol. 1992 Apr;4(2):203–211. doi: 10.1016/0955-0674(92)90034-a. [DOI] [PubMed] [Google Scholar]
  49. Stojilković S. S., Kukuljan M., Iida T., Rojas E., Catt K. J. Integration of cytoplasmic calcium and membrane potential oscillations maintains calcium signaling in pituitary gonadotrophs. Proc Natl Acad Sci U S A. 1992 May 1;89(9):4081–4085. doi: 10.1073/pnas.89.9.4081. [DOI] [PMC free article] [PubMed] [Google Scholar]
  50. Thomas P., Surprenant A., Almers W. Cytosolic Ca2+, exocytosis, and endocytosis in single melanotrophs of the rat pituitary. Neuron. 1990 Nov;5(5):723–733. doi: 10.1016/0896-6273(90)90226-6. [DOI] [PubMed] [Google Scholar]
  51. Thorn P., Petersen O. H. Activation of voltage-sensitive Ca2+ currents by vasopressin in an insulin-secreting cell line. J Membr Biol. 1991 Oct;124(1):63–71. doi: 10.1007/BF01871365. [DOI] [PubMed] [Google Scholar]
  52. Tomasic M., Boyle J. P., Worley J. F., 3rd, Kotlikoff M. I. Contractile agonists activate voltage-dependent calcium channels in airway smooth muscle cells. Am J Physiol. 1992 Jul;263(1 Pt 1):C106–C113. doi: 10.1152/ajpcell.1992.263.1.C106. [DOI] [PubMed] [Google Scholar]
  53. Tsien R. W., Bean B. P., Hess P., Lansman J. B., Nilius B., Nowycky M. C. Mechanisms of calcium channel modulation by beta-adrenergic agents and dihydropyridine calcium agonists. J Mol Cell Cardiol. 1986 Jul;18(7):691–710. doi: 10.1016/s0022-2828(86)80941-5. [DOI] [PubMed] [Google Scholar]
  54. Tsien R. W., Ellinor P. T., Horne W. A. Molecular diversity of voltage-dependent Ca2+ channels. Trends Pharmacol Sci. 1991 Sep;12(9):349–354. doi: 10.1016/0165-6147(91)90595-j. [DOI] [PubMed] [Google Scholar]
  55. Williams M. E., Feldman D. H., McCue A. F., Brenner R., Velicelebi G., Ellis S. B., Harpold M. M. Structure and functional expression of alpha 1, alpha 2, and beta subunits of a novel human neuronal calcium channel subtype. Neuron. 1992 Jan;8(1):71–84. doi: 10.1016/0896-6273(92)90109-q. [DOI] [PubMed] [Google Scholar]
  56. Wilson G. F., Kaczmarek L. K. Mode-switching of a voltage-gated cation channel is mediated by a protein kinase A-regulated tyrosine phosphatase. Nature. 1993 Dec 2;366(6454):433–438. doi: 10.1038/366433a0. [DOI] [PubMed] [Google Scholar]
  57. Yatani A., Codina J., Imoto Y., Reeves J. P., Birnbaumer L., Brown A. M. A G protein directly regulates mammalian cardiac calcium channels. Science. 1987 Nov 27;238(4831):1288–1292. doi: 10.1126/science.2446390. [DOI] [PubMed] [Google Scholar]
  58. Yue D. T., Herzig S., Marban E. Beta-adrenergic stimulation of calcium channels occurs by potentiation of high-activity gating modes. Proc Natl Acad Sci U S A. 1990 Jan;87(2):753–757. doi: 10.1073/pnas.87.2.753. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The EMBO Journal are provided here courtesy of Nature Publishing Group

RESOURCES