[Effects of cryoprotectors on the properties of the mitochondrial membrane surface as determined by distribution in biphasic aqueous systems].

The effects of various cryoprotectors, e. g. dimethylsulfoxide (Me2SO), glycerol, ethylene glycol and polyethylene oxide (PEO, m. w. 400) on the distribution of rat liver mitochondria in a biphasic polymeric PEO 4000-Dextrane 500 system were studied. The type of criss-cross distribution of cryoprotector-treated mitochondria suggests that the isoelectric point for the organelles is shifted towards the acidic values of pH. The effects of these agents decrease in the following order: Me2SO greater PEO-400 greater than glycerol greater than ethylene glycol. The alteration of the distribution coefficient for the mitochondria after their incubation in aqueous polymeric systems in the presence of cryoprotectors is also indicative of a decrease of their surface charge.