Skip to main content
PMC home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1996 Oct 1;496(Pt 1):25–37. doi: 10.1113/jphysiol.1996.sp021662

Ca2+ mobilization and interlayer signal transfer in the heterocellular bilayered epithelium of the rabbit ciliary body.

M Schütte 1, J M Wolosin 1
PMCID: PMC1160821  PMID: 8910193

Abstract

1. 'Ratiometric' fura-2 methodology in slice preparations and 'intensitometric' fluo-3 measurements of confocal images were used to simultaneously monitor Ca2+ mobilization in the two distinct, apically joined cell layers which constitute the ciliary body epithelium (CBE): the non-pigmented (NPE) and pigmented (PE) epithelia. 2. Both methods yielded comparable results regarding Ca2+ responses in the syncytium upon stimulation with adrenergic and cholinergic agonists. 3. The alpha 1-adrenoceptor agonist phenylephrine elicited a moderate [Ca2+]i increase in the PE, whereas NPE [Ca2+]i remained unchanged or exhibited a slight diminution. 4. In combination with carbachol, the alpha 2-adrenoceptor agonist brimonidine elicited large Ca2+ increases (> 10-fold) in both the NPE and PE cell layers, even though previous studies indicated the absence of an alpha 2-adrenergic effect on [Ca2+]i in the PE. The onset, as well as the peak of the Ca2+ responses in PE cells frequently exhibited a small delay with respect to adjacent NPE cells. No such time difference was observed between adjacent NPE cells. 5. Pre-incubation of the ciliary body in Ca(2+)-free solution under conditions known to elicit overt NPE-PE separation abolished the alpha 2-adrenocholinergic response in the PE. 6. Addition of heptanol to the perfusate, to block gap-junctional communication, caused a small [Ca2+]i decrease in the NPE and a slight increase in PE[Ca2+]i. Subsequently, the Ca2+ mobilization in the Pe in response to the brimonidine and carbachol combination was either blocked or showed a substantial delay. The Ca2+ mobilization in the NPE, in contrast, remained unchanged. 7. We conclude that the heterocellular syncytium exhibits rectificatory behaviour with respect to Ca2+ mobilization; responses originating within the NPE are easily transferred to the PE, while the reverse does not occur.

Full text

PDF
25

Images in this article

28Figure 1
on p.28
29Figure 2
on p.29
32Figure 5
on p.32

Selected References

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

  1. Assmann S. M., Wu W. H. Inhibition of guard-cell inward K+ channels by abscisic acid: links and gaps in the signal transduction chain. Symp Soc Exp Biol. 1994;48:193–202. [PubMed] [Google Scholar]
  2. Bastide B., Hervé J. C., Cronier L., Délèze J. Rapid onset and calcium independence of the gap junction uncoupling induced by heptanol in cultured heart cells. Pflugers Arch. 1995 Jan;429(3):386–393. doi: 10.1007/BF00374154. [DOI] [PubMed] [Google Scholar]
  3. Bernardini G., Peracchia C., Peracchia L. L. Reversible effects of heptanol on gap junction structure and cell-to-cell electrical coupling. Eur J Cell Biol. 1984 Jul;34(2):307–312. [PubMed] [Google Scholar]
  4. Berridge M. J. The Albert Lasker Medical Awards. Inositol trisphosphate, calcium, lithium, and cell signaling. JAMA. 1989 Oct 6;262(13):1834–1841. [PubMed] [Google Scholar]
  5. Bill A. Blood circulation and fluid dynamics in the eye. Physiol Rev. 1975 Jul;55(3):383–417. doi: 10.1152/physrev.1975.55.3.383. [DOI] [PubMed] [Google Scholar]
  6. Brubaker R. F. Flow of aqueous humor in humans [The Friedenwald Lecture]. Invest Ophthalmol Vis Sci. 1991 Dec;32(13):3145–3166. [PubMed] [Google Scholar]
  7. Butler G. A., Chen M., Stegman Z., Wolosin J. M. Na(+-) Cl(-)- and HCO3(-)-dependent base uptake in the ciliary body pigment pigment epithelium. Exp Eye Res. 1994 Sep;59(3):343–349. doi: 10.1006/exer.1994.1116. [DOI] [PubMed] [Google Scholar]
  8. Candia O. A., Shi X. P., Chu T. C. Ascorbate-stimulated active Na+ transport in rabbit ciliary epithelium. Curr Eye Res. 1991 Mar;10(3):197–203. doi: 10.3109/02713689109003441. [DOI] [PubMed] [Google Scholar]
  9. Cole D. F. Secretion of the aqueous humour. Exp Eye Res. 1977;25 (Suppl):161–176. doi: 10.1016/s0014-4835(77)80015-8. [DOI] [PubMed] [Google Scholar]
  10. Combettes L., Tran D., Tordjmann T., Laurent M., Berthon B., Claret M. Ca(2+)-mobilizing hormones induce sequentially ordered Ca2+ signals in multicellular systems of rat hepatocytes. Biochem J. 1994 Dec 1;304(Pt 2):585–594. doi: 10.1042/bj3040585. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Danoff S. K., Ross C. A. The inositol trisphosphate receptor gene family: implications for normal and abnormal brain function. Prog Neuropsychopharmacol Biol Psychiatry. 1994 Jan;18(1):1–16. doi: 10.1016/0278-5846(94)90021-3. [DOI] [PubMed] [Google Scholar]
  12. Edelman J. L., Sachs G., Adorante J. S. Ion transport asymmetry and functional coupling in bovine pigmented and nonpigmented ciliary epithelial cells. Am J Physiol. 1994 May;266(5 Pt 1):C1210–C1221. doi: 10.1152/ajpcell.1994.266.5.C1210. [DOI] [PubMed] [Google Scholar]
  13. Ehrlich B. E., Kaftan E., Bezprozvannaya S., Bezprozvanny I. The pharmacology of intracellular Ca(2+)-release channels. Trends Pharmacol Sci. 1994 May;15(5):145–149. doi: 10.1016/0165-6147(94)90074-4. [DOI] [PubMed] [Google Scholar]
  14. FURSHPAN E. J., POTTER D. D. Transmission at the giant motor synapses of the crayfish. J Physiol. 1959 Mar 3;145(2):289–325. doi: 10.1113/jphysiol.1959.sp006143. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Fain G. L., Cilluffo M. C., Fain M. J., Lee D. A. Isolation of non-pigmented epithelial cells from rabbit ciliary body. Invest Ophthalmol Vis Sci. 1988 May;29(5):817–821. [PubMed] [Google Scholar]
  16. Farahbakhsh N. A., Cilluffo M. C. Synergistic effect of adrenergic and muscarinic receptor activation on [Ca2+]i in rabbit ciliary body epithelium. J Physiol. 1994 Jun 1;477(Pt 2):215–221. doi: 10.1113/jphysiol.1994.sp020185. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Giaume C., Korn H. Bidirectional transmission at the rectifying electrotonic synapse: a voltage-dependent process. Science. 1983 Apr 1;220(4592):84–87. doi: 10.1126/science.6298940. [DOI] [PubMed] [Google Scholar]
  18. Giaume C., Korn H. Voltage-dependent dye coupling at a rectifying electrotonic synapse of the crayfish. J Physiol. 1984 Nov;356:151–167. doi: 10.1113/jphysiol.1984.sp015458. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. 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]
  20. Hampson E. C., Vaney D. I., Weiler R. Dopaminergic modulation of gap junction permeability between amacrine cells in mammalian retina. J Neurosci. 1992 Dec;12(12):4911–4922. doi: 10.1523/JNEUROSCI.12-12-04911.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Hansen M., Boitano S., Dirksen E. R., Sanderson M. J. A role for phospholipase C activity but not ryanodine receptors in the initiation and propagation of intercellular calcium waves. J Cell Sci. 1995 Jul;108(Pt 7):2583–2590. doi: 10.1242/jcs.108.7.2583. [DOI] [PubMed] [Google Scholar]
  22. Jacob T. J. Identification of a low-threshold T-type calcium channel in bovine ciliary epithelial cells. Am J Physiol. 1991 Nov;261(5 Pt 1):C808–C813. doi: 10.1152/ajpcell.1991.261.5.C808. [DOI] [PubMed] [Google Scholar]
  23. Lasater E. M., Dowling J. E. Dopamine decreases conductance of the electrical junctions between cultured retinal horizontal cells. Proc Natl Acad Sci U S A. 1985 May;82(9):3025–3029. doi: 10.1073/pnas.82.9.3025. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Margiotta J. F., Walcott B. Conductance and dye permeability of a rectifying electrical synapse. Nature. 1983 Sep 1;305(5929):52–55. doi: 10.1038/305052a0. [DOI] [PubMed] [Google Scholar]
  25. Mills S. L., Massey S. C. Differential properties of two gap junctional pathways made by AII amacrine cells. Nature. 1995 Oct 26;377(6551):734–737. doi: 10.1038/377734a0. [DOI] [PubMed] [Google Scholar]
  26. Minta A., Kao J. P., Tsien R. Y. Fluorescent indicators for cytosolic calcium based on rhodamine and fluorescein chromophores. J Biol Chem. 1989 May 15;264(14):8171–8178. [PubMed] [Google Scholar]
  27. Nicholls J. G., Purves D. Monosynaptic chemical and electrical connexions between sensory and motor cells in the central nervous system of the leech. J Physiol. 1970 Aug;209(3):647–667. doi: 10.1113/jphysiol.1970.sp009184. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Oh J., Krupin T., Tang L. Q., Sveen J., Lahlum R. A. Dye coupling of rabbit ciliary epithelial cells in vitro. Invest Ophthalmol Vis Sci. 1994 Apr;35(5):2509–2514. [PubMed] [Google Scholar]
  29. Peracchia C., Peracchia L. L. Gap junction dynamics: reversible effects of divalent cations. J Cell Biol. 1980 Dec;87(3 Pt 1):708–718. doi: 10.1083/jcb.87.3.708. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Peracchia C., Peracchia L. L. Gap junction dynamics: reversible effects of hydrogen ions. J Cell Biol. 1980 Dec;87(3 Pt 1):719–727. doi: 10.1083/jcb.87.3.719. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Piccolino M., Neyton J., Gerschenfeld H. M. Decrease of gap junction permeability induced by dopamine and cyclic adenosine 3':5'-monophosphate in horizontal cells of turtle retina. J Neurosci. 1984 Oct;4(10):2477–2488. doi: 10.1523/JNEUROSCI.04-10-02477.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Raviola G., Raviola E. Intercellular junctions in the ciliary epithelium. Invest Ophthalmol Vis Sci. 1978 Oct;17(10):958–981. [PubMed] [Google Scholar]
  33. Ringham G. L. Localization and electrical characteristics of a giant synapse in the spinal cord of the lamprey. J Physiol. 1975 Oct;251(2):395–407. doi: 10.1113/jphysiol.1975.sp011100. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Schütte M., Diadori A., Wang C., Wolosin J. M. Comparative adrenocholinergic control of intracellular Ca2+ in the layers of the ciliary body epithelium. Invest Ophthalmol Vis Sci. 1996 Jan;37(1):212–220. [PubMed] [Google Scholar]
  35. Shi X. P., Zamudio A. C., Candia O. A., Wolosin J. M. Adreno-cholinergic modulation of junctional communications between the pigmented and nonpigmented layers of the ciliary body epithelium. Invest Ophthalmol Vis Sci. 1996 May;37(6):1037–1046. [PubMed] [Google Scholar]
  36. Sugrue M. F. The pharmacology of antiglaucoma drugs. Pharmacol Ther. 1989;43(1):91–138. doi: 10.1016/0163-7258(89)90049-1. [DOI] [PubMed] [Google Scholar]
  37. TORMEY J. M. Fine structure of the ciliary epithelium of the rabbit, with particular reference to "infoldedmembranes," "vesicles," and the effects of Diamox. J Cell Biol. 1963 Jun;17:641–659. doi: 10.1083/jcb.17.3.641. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Teranishi T., Negishi K., Kato S. Dopamine modulates S-potential amplitude and dye-coupling between external horizontal cells in carp retina. Nature. 1983 Jan 20;301(5897):243–246. doi: 10.1038/301243a0. [DOI] [PubMed] [Google Scholar]
  39. Toris C. B., Gleason M. L., Camras C. B., Yablonski M. E. Effects of brimonidine on aqueous humor dynamics in human eyes. Arch Ophthalmol. 1995 Dec;113(12):1514–1517. doi: 10.1001/archopht.1995.01100120044006. [DOI] [PubMed] [Google Scholar]
  40. Wolosin J. M., Chen M., Gordon R. E., Stegman Z., Butler G. A. Separation of the rabbit ciliary body epithelial layers in viable form: identification of differences in bicarbonate transport. Exp Eye Res. 1993 Apr;56(4):401–409. doi: 10.1006/exer.1993.1054. [DOI] [PubMed] [Google Scholar]
  41. Wolosin J. M. Gap junctions in rabbit corneal epithelium: limited permeability and inhibition by cAMP. Am J Physiol. 1991 Nov;261(5 Pt 1):C857–C864. doi: 10.1152/ajpcell.1991.261.5.C857. [DOI] [PubMed] [Google Scholar]
  42. von Gersdorff H., Matthews G. Dynamics of synaptic vesicle fusion and membrane retrieval in synaptic terminals. Nature. 1994 Feb 24;367(6465):735–739. doi: 10.1038/367735a0. [DOI] [PubMed] [Google Scholar]

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

RESOURCES