| Popis: |
By light scattering method it was shown, that vesicles, obtained by sonication of rod outer segment membranes in different ionic media rapidly and irreversibly increased their volume under bleaching of rhodopsin. Apparently, this volume change was caused by the increase in the amount of free ions in vesicles under illumination. The photoinduced volume change was practically the same in all cases studied (equal ionic constitutions inside and outside of vesicles; in the presence of penetrating anion SCN-; under ionic gradients on vesicle membranes; in the presence of ionophores which induce the permeability for K+ and H+) and corresponds to the appearance of no more than one ion inside the vesicle under bleaching of one rhodopsin molecule. The obtained results testify against the hypothesis, that bleaching of rhodopsin induce essential increase in ionic permeability of rod outer segment disk membranes. |
