Illumination of retinal discs from dark adapted frogs caused a rapid and transient alkalinization of the suspension medium, followed by a slower and more prolonged acidification. Pretreatment with valinomycin, gramicidin or a proton conductor did not change this pattern, but the initial proton uptake was prevented by concentrations of a detergent or alcohol that had no effect on the acidification process. The initial transient proton uptake corresponded to a minimum of 5.7 H+ taken up per rhodopsin bleached, with an elevation of this stoichiometry at early times of illumination. It is suggested that bleaching of rhodopsin contained in retinal discs initiates a transmembrane ion flux that is reflected by a net proton entry.
|Original language||English (US)|
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Mar 28 1980|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology