MEMBRANE SPECIFICITY OF NONMONOTONIC TRENDS IN CATION-MEDIATED INJURY TO RAPIDLY FROZEN PHOSPHOLIPID-VESICLES

Phospholipid vesicles like erythrocyte ghosts [1] have been shown to display trends in freeze-thaw injury with Group I ions which are non-monotonic in nature. That is to say, the relative extent of injury with such ions, measured as calcein release, does not follow a lyotropic series related solely to the hydrated ionic radii of these ions. By incorporation of cholesterol into the vesicles the non-monotonic nature of these trends has been shown to be highly membrane specific. Thus the non-monotonic trends in cation mediated freeze-thaw injury are shown to be independent of bulk solution properties.