CA-EFFLUX, FROM DIRECT MEMBRANE INJURY BY CCL4, IS ELICITED BY AMPHIPHILIC VEHICLES IN-VITRO

Direct membrane injury by CCl4, in situations excluding metabolic acti vation, was evaluated in saponin-permeabilized hepatocytes and in micr osomes by measuring immediate Ca2+ efflux. A good correlation appears between the Ca2+ efflux and the level of CCl4 in the membrane and also the variations in fluidity. Mixtures of CCl4 with water-soluble vehic les were used to improve the dispersion of CCl4 in the medium. The mix tures varied in their ability to elicit the membrane effects of CCl4. The performance of ethanol and, to a lesser degree, other alcohols, su ggests the existence of a water stable structural organization between CCl4 and these amphiphilic vehicles, facilitating the transfer of CCl 4 to the membrane.