par Deleers, Michel 
;Couturier, Etienne ;Malaisse, Willy
Référence Cell calcium, 2, page (159-171)
Publication Publié, 1981
;Couturier, Etienne ;Malaisse, Willy Référence Cell calcium, 2, page (159-171)
Publication Publié, 1981
Article révisé par les pairs
| Résumé : | The antibiotic ionophore ionomycin translocates Ca from an aqueous medium into or across an organic immiscible phase. At pH 8.0, ionomycin translocates less Ca than A23187, the effects of these ionophores being additive to one another. The capacity of ionomycin to translocate Ca across the organic phase is dramatically decreased when the pH of the aqueous media is reduced from 8.0 to 7.5 or lower values. Ionomycin also mediates Ca exchange-diffusion in liposomes, the magnitude of such a process being greater in fluid than in rigid liposomes. At a physiological pH (7.4), ionomycin is unexpectedly as potent as A23187 in mediating Ca transport in fluid liposomes. These findings suggest that the capacity of ionophores to translocate Ca across model membranes depends on both the transverse and lateral mobility of the ionophoretic molecules. The relative importance of the latter phenomenon itself largely depends on the stoichiometry of the Ca-ionophore complex. © 1981. |
