Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Science 26 June 1987:
Vol. 236. no. 4809, pp. 1674 - 1678
DOI: 10.1126/science.3037695
Prev | Table of Contents | Next

Articles

Science, Vol 236, Issue 4809, 1674-1678
Copyright © 1987 by American Association for the Advancement of Science

articles

Divalent cations directly affect the conductance of excised patches of rod photoreceptor membrane

JH Stern, H Knutsson, and PR MacLeish

Phototransduction in rod cells is likely to involve an intracellular messenger system that links the absorption of light by rhodopsin to a change in membrane conductance. The direct effect of guanosine 3',5'-monophosphate (cGMP) on excised patches of rod outer segment membrane strongly supports a role for cGMP as an intracellular messenger in phototransduction. It is reported here that magnesium and calcium directly affect the conductance of excised patches of rod membrane in the absence of cGMP and that magnesium, applied to intact rod cells, blocks a component of the cellular light response. The divalent cation-suppressed conductance in excised patches showed outward rectification and cation-selective permeability resembling those of the light-suppressed conductance measured from the intact rod cell. The divalent cation-suppressed conductance was partly blocked by a concentration of the pharmacological agent L-cis-diltiazem that blocked all of the cGMP-activated conductance. Divalent cations may act, together with cGMP, as an intracellular messenger system that mediates the light response of the rod photoreceptor cell.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Lotus japonicus CASTOR and POLLUX Are Ion Channels Essential for Perinuclear Calcium Spiking in Legume Root Endosymbiosis.
M. Charpentier, R. Bredemeier, G. Wanner, N. Takeda, E. Schleiff, and M. Parniske (2008)
PLANT CELL 20, 3467-3479
   Abstract »    Full Text »    PDF »
Structural insight into Ca2+ specificity in tetrameric cation channels.
A. Alam, N. Shi, and Y. Jiang (2007)
PNAS 104, 15334-15339
   Abstract »    Full Text »    PDF »
Influence of Permeant Ions on Gating in Cyclic Nucleotide-gated Channels.
M. Holmgren (2002)
J. Gen. Physiol. 121, 61-72
   Abstract »    Full Text »    PDF »
Electrical and Biochemical Properties of the cGMP-gated Cation Channel from Rod Photoreceptors.
U.B. Kaupp, W. Hanke, R. Simmoteit, and H. Luhring (1988)
Cold Spring Harb Symp Quant Biol 53, 407-415
   Abstract »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)