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Light-dependent calcium release from photoreceptors measured by laser micro-mass analysis


Yoshikami and Hagins1 first suggested that calcium is sequestered within membranous disks in the outer segments of vertebrate rods and that the bleaching of visual pigment molecules by light causes the release of Ca from the disks. Once released, the Ca was postulated to bind to Na+ channels or carrier molecules in the plasma membrane to produce the electrical response. This theory, termed the ‘calcium hypothesis’, is supported by much evidence2–5 but remains controversial, largely because of the difficulty in measuring calcium in rods and of demonstrating light-induced release6–14. Here we describe direct measurements of total rod Ca using a new microprobe method, called laser micro-mass analysis, or LAMMA. Using this technique, we show that rods contain large amounts of Ca concentrated in their outer segments. Physiological levels of illumination produce a graded efflux of rod Ca content, amounting to about 104 ions per rhodopsin molecule bleached in dim light. As light does not change the rate of Ca influx, the total Ca content of the rod decreases. In bright light, as much as half the total Ca leaves the rod during only l min of illumination.

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  1. Yoshikami, S. & Hagins, W. A. Biophys. Soc. Abstr. 15, 472 (1971).

    Google Scholar 

  2. Miller, W. H. Molecular Mechanisms of Photoreceptor Transduction (Academic, New York, 1981).

    Google Scholar 

  3. Hubbell, W. L. & Bownds, M. D. A. Rev. Neurosci. 2, 17–34 (1979).

    Article  CAS  Google Scholar 

  4. Fatt, P. FEBS Lett. 149, 159–166 (1982).

    Article  CAS  Google Scholar 

  5. George, J. S. & Hagins, W. A. Nature 303, 344–348 (1983).

    Article  ADS  CAS  Google Scholar 

  6. Hagins, W. A. & Yoshikami, S. Ann. N.Y. Acad. Sci. 264, 314–325 (1975).

    Article  ADS  CAS  Google Scholar 

  7. Kaufmann, R. Scanning Electron Microscopy Vol. 2, 641–644 (AMF O'Hare, Chicago, 1980).

    Google Scholar 

  8. Schnetkamp, P. P. M., Daemen, F. J. M. & Bonting, S. L. Biochim. biophys. Acta 468, 259–270 (1977).

    Article  CAS  Google Scholar 

  9. Liebman, P. A. Invest. Ophthal. vis. Sci. 13, 700–701 (1974).

    CAS  Google Scholar 

  10. Szuts, E. Z. & Cone, R. A. Biochim. biophys. Acta 468, 194–208 (1977).

    Article  CAS  Google Scholar 

  11. Szuts, E. J. J. gen. Physiol. 76, 253–286 (1980).

    Article  CAS  Google Scholar 

  12. Hess, H. H. Expl Eye Res. 21, 471–479 (1975).

    Article  CAS  Google Scholar 

  13. Noell, G., Stieve, H. & Winterhager, J. Biophys. Struct. Mechanism 5, 43–53 (1979).

    Article  CAS  Google Scholar 

  14. Schnetkamp, P. P. M. Biochim. biophys. Acta 598, 66–90 (1980).

    Article  CAS  Google Scholar 

  15. Vogt, H., Keinen, H. J., Meier, S. & Wechsung, R. Z. analyt. Chem. 308, 195–200 (1981).

    Article  CAS  Google Scholar 

  16. Schröder, W. H. Z. analyt. Chem. 308, 212–217 (1981).

    Article  Google Scholar 

  17. Fein, A. & Szuts, E. Z. Photoreceptors: Their Role in Vision (Cambridge University Press, 1982).

    Google Scholar 

  18. Gold, G. H. & Korenbrot, J. I. Proc. natn. Acad. Sci. U.S.A. 77, 5557–5561 (1980).

    Article  ADS  CAS  Google Scholar 

  19. Schröder, W.H. & Fain, G. L. Biophys. J. 45, 341a (1984).

  20. Roof, D. & Heuser, J. E. J. Cell Biol. 95, 487–500 (1982).

    Article  CAS  Google Scholar 

  21. Usukura, J. & Yamada, E. Biomed. Res. 2(2), 177–193 (1981).

    Article  CAS  Google Scholar 

  22. Woodruff, M. L., Fain, G. L. & Bastian, B. L. J. gen. Physiol. 80, 517–536 (1982).

    Article  CAS  Google Scholar 

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Schröder, W., Fain, G. Light-dependent calcium release from photoreceptors measured by laser micro-mass analysis. Nature 309, 268–270 (1984).

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