Bile Acids as Inducers of Protonophore and Ionophore Permeability of Biological and Artificial Membranes

Abstract

It is now generally accepted that the role of bile acids in the organism is not limited to their participation in the process of food digestion. Indeed, bile acids are signaling molecules and being amphiphilic compounds, are also capable of modifying the properties of cell membranes and their organelles. This review is devoted to the analysis of data on the interaction of bile acids with biological and artificial membranes, in particular, their protonophore and ionophore effects. The effects of bile acids were analyzed depending on their physicochemical properties: namely the structure of their molecules, indicators of the hydrophobic–hydrophilic balance, and the critical micelle concentration. Particular attention is paid to the interaction of bile acids with the powerhouse of cells, the mitochondria. It is of note that bile acids, in addition to their protonophore and ionophore actions, can also induce Ca2+-dependent nonspecific permeability of the inner mitochondrial membrane. We consider the unique action of ursodeoxycholic acid as an inducer of potassium conductivity of the inner mitochondrial membrane. We also discuss a possible relationship between this K+ ionophore action of ursodeoxycholic acid and its therapeutic effects.

Effect of Bile on Hemodynamics and Blood Micro-Rheological Parameters in Experimental Models of Bilhemia

“…This raises cytosolic Ca 2+ activity and ultimately causes eryptosis, the suicidal death of erythrocytes marked by the exposure of phosphatidylserine on the cell surface [65,66]. It was demonstrated that bile salt-associated hemolysis is partially calcium-mediated [66,67]. Moreover, the bile acid concentrations needed to induce eryptosis are greater than those needed to cause hemolysis [65].…”