Abstract
Previous work has suggested that a Na–Ca exchanger may have a key role in visual transduction in retinal rods1–10. This exchanger is thought to maintain a low internal free Ca2+ concentration in darkness4–10 and to contribute to the rod's recovery after light by removing any internally released Ca2+ (refs 1, 2, 6–8). Little else is known about this transport mechanism in rods. We describe here an inward membrane current recorded from single isolated rods which appears to be associated with such external Na+-dependent Ca2+ efflux activity. External Na+, but not Li+, could generate this current; high external K+ inhibited it while small amounts of La3+ (10 µM) completely abolished it. The exchanger can also transport Sr2+, but not Ba2+ or other divalent cations. The exchange ratio was estimated to be 3Na+:1Ca2+. As well as demonstrating clearly the Na–Ca exchanger in the rod outer segment, our experiments also cast serious doubt on the commonly held view that light simply releases internal Ca2+ to bind to and block the light-sensitive conductance.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Yoshikami, S., George, J. S. & Hagins, W. A. Nature 286, 395–398 (1980).
Gold, G. H. & Korenbrot, J. I. Proc. natn. Acad. Sci. U.S.A. 77, 5557–5561 (1980).
Schnetkamp, P. P. M., Daemen, F. J. M. & Bonting, S. L. Biochim. biophys. Acta 468, 259–270 (1977).
Fain, G. L. & Lisman, J. E. Prog. Biophys. molec. Biol. 37, 91–147 (1981).
Bastian, B. L. & Fain, G. L. J. Physiol., Lond. 330, 331–347 (1982).
Yau, K.-W., McNaughton, P. A. & Hodgkin, A. L. Nature 292, 502–505 (1981).
Hodgkin, A. L., McNaughton, P. A., Nunn, B. J. & Yau, K.-W. J. Physiol., Lond. 350, 649–680 (1984).
Schröder, W. H. & Fain, G. L. Nature 309, 268–270 (1984).
Yau, K.-W. & Nakatani, K. Nature 309, 352–354 (1984).
Hodgkin, A. L., McNaughton, P. A. & Nunn, B. J. J. Physiol., Lond. (in the press).
Baylor, D. A. & Lamb, T. D. J. Physiol., Lond. 328, 49–71 (1982).
Baylor, D. A. & Nunn, B. J. J. Physiol., Lond. (in the press).
Meech, R. W. A. Rev. Biophys. Bioengng 7, 1–18 (1978).
Blaustein, M. P. & Hodgkin, A. L. J. Physiol., Lond. 200, 497–527 (1969).
Blaustein, M. P. in Electrogenic Transport: Fundamental Principles and Physiological Implications (eds Blaustein, M. P. & Lieberman, M.) 129–147 (Raven, New York, 1984).
Cervetto, L. & McNaughton, P. A. J. Physiol., Lond. 341, 75–76P (1983).
Blaustein, M. P. & Russell, J. M. J. Membrane Biol. 22, 285–312 (1975).
Baker, P. & McNaughton, P. A. J. Physiol., Lond. 276, 127–150 (1978).
Hagins, W. A. & Yoshikami, S. Expl Eye Res. 18, 299–305 (1974).
Brown, J. E., Coles, J. A. & Pinto, L. H. J. Physiol., Lond. 269, 707–722 (1977).
MacLeish, P. R., Schwartz, E. A. & Tachibana, M. J. Physiol., Lond. 348, 645–664 (1984).
Baylor, D. A., Lamb, T. D. & Yau, K.-W. J. Physiol., Lond. 288, 612–634 (1979).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Yau, KW., Nakatani, K. Electrogenic Na–Ca exchange in retinal rod outer segment. Nature 311, 661–663 (1984). https://doi.org/10.1038/311661a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/311661a0
This article is cited by
-
Investigating the Ca2+-dependent and Ca2+-independent mechanisms for mammalian cone light adaptation
Scientific Reports (2018)
-
Modulation of the reaction cycle of the Na+:Ca2+, K+ exchanger
European Biophysics Journal (2007)
-
Membrane protein diffusion sets the speed of rod phototransduction
Nature (2001)
-
Methodical approaches to identification of transmembrane current of sodium-calcium exchange
Neurophysiology (1998)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.