Correlation between the n-alkanols-induced sensitization of erythrocytes to hyperthermia and the fluidization of their membrane

Abstract

It was reported recently that the thermohaemolysis of mammalian erythrocytes is related to a thermo-induced membrane event of permeability barrier impairment in which the inactivation of membrane proteins is implicated. Here, the influence of different n-alkanols, methanol to octanol, on the onset temperature T_m of this barrier impairment event was compared with the changes in the dynamic properties of the membrane lipid region for human erythrocytes. The potencies of these n-alkanols to decrease T_m, to fluidize and disorder the lipid region were strongly related to their lipid solubilities. With respect to their membrane concentration, all the applied n-alkanols were roughly equipotent in decreasing T_m and in fluidizing and disordering the membrane lipids. Since T_m corresponds to the stability of erythrocytes against hyperthermia, this result indicates that the heat sensitization of these cells, induced by the n-alkanols employed, strongly correlated the fluidization (disordering) of the lipid region of their membranes.

Key Words:

• Thermostability
• erythrocyte membrane
• n-alkanols
• temperature of barrier impairment
• fluidity
• lipid region disordering