Skip to main content
PMC home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1989 Aug;415:143–158. doi: 10.1113/jphysiol.1989.sp017716

Voltage-gated and agonist-mediated rises in intracellular Ca2+ in rat clonal pituitary cells (GH3) held under voltage clamp.

C D Benham 1
PMCID: PMC1189171  PMID: 2517986

Abstract

1. Intracellular free calcium (Ca2+i) was estimated in single GH3 cells by dual wavelength emission spectrofluorimetry using the Ca2+ indicator dye Indo-1, while cells were held under voltage clamp using patch clamp techniques. 2. Depolarization of cells evoked a transient rise in Ca2+i that increased with increasing duration of depolarization to a peak at about 10 s. 3. Calcium transients showed a bell-shaped dependence on the amplitude of the depolarizing pulse. They were abolished in the absence of extracellular calcium and by application of 10 microM-nifedipine. 4. Thyrotrophin-releasing hormone (TRH) evoked a transient rise in Ca2+i that was followed by a more sustained period of elevated Ca2+i in some cells. The transient phase of the response but not the sustained phase was seen in the absence of extracellular calcium. 5. Ca2+i transients evoked by depolarization were not affected by pre-release of internal Ca2+ stores with TRH. 6. The results demonstrate that voltage-gated Ca2+ entry and Ca2+ store release can each elevate cytoplasmic free calcium in GH3 cells and may both be important for stimulus-secretion coupling. Non-voltage-gated Ca2+ entry is not a major source of Ca2+ under these conditions.

Full text

PDF
149

Selected References

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

  1. Almers W., Neher E. The Ca signal from fura-2 loaded mast cells depends strongly on the method of dye-loading. FEBS Lett. 1985 Nov 11;192(1):13–18. doi: 10.1016/0014-5793(85)80033-8. [DOI] [PubMed] [Google Scholar]
  2. Barcenas-Ruiz L., Wier W. G. Voltage dependence of intracellular [Ca2+]i transients in guinea pig ventricular myocytes. Circ Res. 1987 Jul;61(1):148–154. doi: 10.1161/01.res.61.1.148. [DOI] [PubMed] [Google Scholar]
  3. Callewaert G., Cleemann L., Morad M. Epinephrine enhances Ca2+ current-regulated Ca2+ release and Ca2+ reuptake in rat ventricular myocytes. Proc Natl Acad Sci U S A. 1988 Mar;85(6):2009–2013. doi: 10.1073/pnas.85.6.2009. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Cobbold P. H., Rink T. J. Fluorescence and bioluminescence measurement of cytoplasmic free calcium. Biochem J. 1987 Dec 1;248(2):313–328. doi: 10.1042/bj2480313. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Cohen C. J., McCarthy R. T. Nimodipine block of calcium channels in rat anterior pituitary cells. J Physiol. 1987 Jun;387:195–225. doi: 10.1113/jphysiol.1987.sp016570. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Drummond A. H. Bidirectional control of cytosolic free calcium by thyrotropin-releasing hormone in pituitary cells. 1985 Jun 27-Jul 3Nature. 315(6022):752–755. doi: 10.1038/315752a0. [DOI] [PubMed] [Google Scholar]
  7. Dubinsky J. M., Oxford G. S. Dual modulation of K channels by thyrotropin-releasing hormone in clonal pituitary cells. Proc Natl Acad Sci U S A. 1985 Jun;82(12):4282–4286. doi: 10.1073/pnas.82.12.4282. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Dufy B., Jaken S., Barker J. L. Intracellular Ca2+-dependent protein kinase C activation mimics delayed effects of thyrotropin-releasing hormone on clonal pituitary cell excitability. Endocrinology. 1987 Aug;121(2):793–802. doi: 10.1210/endo-121-2-793. [DOI] [PubMed] [Google Scholar]
  9. Fernandez J. M., Neher E., Gomperts B. D. Capacitance measurements reveal stepwise fusion events in degranulating mast cells. 1984 Nov 29-Dec 5Nature. 312(5993):453–455. doi: 10.1038/312453a0. [DOI] [PubMed] [Google Scholar]
  10. Gershengorn M. C. Mechanism of thyrotropin releasing hormone stimulation of pituitary hormone secretion. Annu Rev Physiol. 1986;48:515–526. doi: 10.1146/annurev.ph.48.030186.002503. [DOI] [PubMed] [Google Scholar]
  11. Gershengorn M. C., Thaw C. Thyrotropin-releasing hormone (TRH) stimulates biphasic elevation of cytoplasmic free calcium in GH3 cells. Further evidence that TRH mobilizes cellular and extracellular Ca2+. Endocrinology. 1985 Feb;116(2):591–596. doi: 10.1210/endo-116-2-591. [DOI] [PubMed] [Google Scholar]
  12. Gray P. T. Oscillations of free cytosolic calcium evoked by cholinergic and catecholaminergic agonists in rat parotid acinar cells. J Physiol. 1988 Dec;406:35–53. doi: 10.1113/jphysiol.1988.sp017367. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Grynkiewicz G., Poenie M., Tsien R. Y. A new generation of Ca2+ indicators with greatly improved fluorescence properties. J Biol Chem. 1985 Mar 25;260(6):3440–3450. [PubMed] [Google Scholar]
  14. Hagiwara S., Ohmori H. Studies of calcium channels in rat clonal pituitary cells with patch electrode voltage clamp. J Physiol. 1982 Oct;331:231–252. doi: 10.1113/jphysiol.1982.sp014371. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Horn R., Marty A. Muscarinic activation of ionic currents measured by a new whole-cell recording method. J Gen Physiol. 1988 Aug;92(2):145–159. doi: 10.1085/jgp.92.2.145. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Jackson A. P., Timmerman M. P., Bagshaw C. R., Ashley C. C. The kinetics of calcium binding to fura-2 and indo-1. FEBS Lett. 1987 May 25;216(1):35–39. doi: 10.1016/0014-5793(87)80752-4. [DOI] [PubMed] [Google Scholar]
  17. Jacob R., Merritt J. E., Hallam T. J., Rink T. J. Repetitive spikes in cytoplasmic calcium evoked by histamine in human endothelial cells. Nature. 1988 Sep 1;335(6185):40–45. doi: 10.1038/335040a0. [DOI] [PubMed] [Google Scholar]
  18. Kidokoro Y. Spontaneous calcium action potentials in a clonal pituitary cell line and their relationship to prolactin secretion. Nature. 1975 Dec 25;258(5537):741–742. doi: 10.1038/258741a0. [DOI] [PubMed] [Google Scholar]
  19. Lamb T. D. An inexpensive digital tape recorder suitable for neurophysiological signals. J Neurosci Methods. 1985 Oct;15(1):1–13. doi: 10.1016/0165-0270(85)90057-3. [DOI] [PubMed] [Google Scholar]
  20. Lindau M., Fernandez J. M. IgE-mediated degranulation of mast cells does not require opening of ion channels. Nature. 1986 Jan 9;319(6049):150–153. doi: 10.1038/319150a0. [DOI] [PubMed] [Google Scholar]
  21. Marchetti C., Brown A. M. Protein kinase activator 1-oleoyl-2-acetyl-sn-glycerol inhibits two types of calcium currents in GH3 cells. Am J Physiol. 1988 Jan;254(1 Pt 1):C206–C210. doi: 10.1152/ajpcell.1988.254.1.C206. [DOI] [PubMed] [Google Scholar]
  22. Mason W. T., Waring D. W. Patch clamp recordings of single ion channel activation by gonadotrophin-releasing hormone in ovine pituitary gonadotrophs. Neuroendocrinology. 1986;43(2):205–219. doi: 10.1159/000124529. [DOI] [PubMed] [Google Scholar]
  23. Ozawa S. Biphasic effect of thyrotropin-releasing hormone on membrane K+ permeability in rat clonal pituitary cells. Brain Res. 1981 Mar 23;209(1):240–244. doi: 10.1016/0006-8993(81)91188-4. [DOI] [PubMed] [Google Scholar]
  24. 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]
  25. Penner R., Matthews G., Neher E. Regulation of calcium influx by second messengers in rat mast cells. Nature. 1988 Aug 11;334(6182):499–504. doi: 10.1038/334499a0. [DOI] [PubMed] [Google Scholar]
  26. Rebecchi M. J., Gershengorn M. C. Thyroliberin stimulates rapid hydrolysis of phosphatidylinositol 4,5-bisphosphate by a phosphodiesterase in rat mammotropic pituitary cells. Evidence for an early Ca2+-independent action. Biochem J. 1983 Nov 15;216(2):287–294. doi: 10.1042/bj2160287. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. 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]
  28. Thorner M. O., Hackett J. T., Murad F., MacLeod R. M. Calcium rather than cyclic AMP as the physiological intracellular regulator of prolactin release. Neuroendocrinology. 1980 Dec;31(6):390–402. doi: 10.1159/000123109. [DOI] [PubMed] [Google Scholar]
  29. Woods N. M., Cuthbertson K. S., Cobbold P. H. Repetitive transient rises in cytoplasmic free calcium in hormone-stimulated hepatocytes. Nature. 1986 Feb 13;319(6054):600–602. doi: 10.1038/319600a0. [DOI] [PubMed] [Google Scholar]
  30. Yakel J. L., Trussell L. O., Jackson M. B. Three serotonin responses in cultured mouse hippocampal and striatal neurons. J Neurosci. 1988 Apr;8(4):1273–1285. doi: 10.1523/JNEUROSCI.08-04-01273.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

RESOURCES