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. 1980 Sep;77(9):5557–5561. doi: 10.1073/pnas.77.9.5557

Light-induced calcium release by intact retinal rods.

G H Gold, J I Korenbrot
PMCID: PMC350101  PMID: 6776539

Abstract

Brief illumination of the isolated toad retina produces a transient increase in the extracellular free Ca concentration in the photoreceptor layer. This change in concentration arises from the release of Ca2+ by the rod outer segments. The release begins within 200 msec after the stimulus flash. The peak amplitude of the concentration change increases linearly with light intensity up to approximately 100 absorbed photons per rod and saturates at about 10(7) absorbed photons per rod. In the linear range, the amount of Ca released corresponds to about 2 x 10(4) Ca2+ per absorbed photon per rod. The high stoichiometry of this release, in relation to the low free intracellular Ca concentration, suggests that the release reflects a light-dependent increase in the intracellular free Ca concentration. This light-activated Ca release occurs in the absence of a detectable receptor potential (in low-Na Ringer's solution) and, therefore, must reflect one of the initial stages in the transduction process.

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Selected References

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

  1. Baylor D. A., Lamb T. D., Yau K. W. The membrane current of single rod outer segments. J Physiol. 1979 Mar;288:589–611. [PMC free article] [PubMed] [Google Scholar]
  2. Blaustein M. P. The interrelationship between sodium and calcium fluxes across cell membranes. Rev Physiol Biochem Pharmacol. 1974;70:33–82. doi: 10.1007/BFb0034293. [DOI] [PubMed] [Google Scholar]
  3. Brown J. E., Coles J. A., Pinto L. H. Effects of injections of calcium and EGTA into the outer segments of retinal rods of Bufo marinus. J Physiol. 1977 Aug;269(3):707–722. doi: 10.1113/jphysiol.1977.sp011924. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Brown J. E., Pinto L. H. Ionic mechanism for the photoreceptor potential of the retina of Bufo marinus. J Physiol. 1974 Feb;236(3):575–591. doi: 10.1113/jphysiol.1974.sp010453. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Fain G. L. Sensitivity of toad rods: Dependence on wave-length and background illumination. J Physiol. 1976 Sep;261(1):71–101. doi: 10.1113/jphysiol.1976.sp011549. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Goridis C. The effect of flash illumination on the endogenous cyclic GMP content of isolated frog retinae. Exp Eye Res. 1977 Feb;24(2):171–177. doi: 10.1016/0014-4835(77)90257-3. [DOI] [PubMed] [Google Scholar]
  7. Hagins W. A. The visual process: Excitatory mechanisms in the primary receptor cells. Annu Rev Biophys Bioeng. 1972;1:131–158. doi: 10.1146/annurev.bb.01.060172.001023. [DOI] [PubMed] [Google Scholar]
  8. Hagins W. A., Yoshikami S. Ionic mechanisms in excitation of photoreceptors. Ann N Y Acad Sci. 1975 Dec 30;264:314–325. doi: 10.1111/j.1749-6632.1975.tb31492.x. [DOI] [PubMed] [Google Scholar]
  9. Hagins W. A., Yoshikami S. Proceedings: A role for Ca2+ in excitation of retinal rods and cones. Exp Eye Res. 1974 Mar;18(3):299–305. doi: 10.1016/0014-4835(74)90157-2. [DOI] [PubMed] [Google Scholar]
  10. Hubbell W. L., Bownds M. D. Visual transduction in vertebrate photoreceptors. Annu Rev Neurosci. 1979;2:17–34. doi: 10.1146/annurev.ne.02.030179.000313. [DOI] [PubMed] [Google Scholar]
  11. Hárosi F. I. Absorption spectra and linear dichroism of some amphibian photoreceptors. J Gen Physiol. 1975 Sep;66(3):357–382. doi: 10.1085/jgp.66.3.357. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Kilbride P., Ebrey T. G. Light-initiated changes of cyclic guanosine monophosphate levels in the frog retina measured with quick-freezing techniques. J Gen Physiol. 1979 Sep;74(3):415–426. doi: 10.1085/jgp.74.3.415. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Korenbrot J. I., Cone R. A. Dark ionic flux and the effects of light in isolated rod outer segments. J Gen Physiol. 1972 Jul;60(1):20–45. doi: 10.1085/jgp.60.1.20. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Mitzel D. L., Hall I. A., DeVries G. W., Cohen A. I., Ferrendelli J. A. Comparison of cyclic nucleotide and energy metabolism of intact mouse retina in situ and in vitro. Exp Eye Res. 1978 Jul;27(1):27–37. doi: 10.1016/0014-4835(78)90050-7. [DOI] [PubMed] [Google Scholar]
  15. Montal M. Rhodopsin in model membranes. Biochim Biophys Acta. 1979 Aug 20;559(2-3):231–257. doi: 10.1016/0304-4157(79)90003-0. [DOI] [PubMed] [Google Scholar]
  16. Szuts E. Z., Cone R. A. Calcium content of frog rod outer segments and discs. Biochim Biophys Acta. 1977 Jul 14;468(2):194–208. doi: 10.1016/0005-2736(77)90114-6. [DOI] [PubMed] [Google Scholar]
  17. Tomita T. Electrical activity of vertebrate photoreceptors. Q Rev Biophys. 1970 May;3(2):179–222. doi: 10.1017/s0033583500004571. [DOI] [PubMed] [Google Scholar]
  18. Woodruff M. L., Bownds M. D. Amplitude, kinetics, and reversibility of a light-induced decrease in guanosine 3',5'-cyclic monophosphate in frog photoreceptor membranes. J Gen Physiol. 1979 May;73(5):629–653. doi: 10.1085/jgp.73.5.629. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Wormington C. M., Cone R. A. Ionic blockage of the light-regulated sodium channels in isolated rod outer segments. J Gen Physiol. 1978 Jun;71(6):657–681. doi: 10.1085/jgp.71.6.657. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Yoshikami S., George J. S., Hagins W. A. Light-induced calcium fluxes from outer segment layer of vertebrate retinas. Nature. 1980 Jul 24;286(5771):395–398. doi: 10.1038/286395a0. [DOI] [PubMed] [Google Scholar]

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