Glycerol Transport in Mitochondria

Abstract

The entry of glycerol molecules in unphosphorylated form into mitochondria was studied. The effective binding of glycerol with membranes of rat liver mitochondria was demonstrated using spectrofluorimetry and FTIR spectroscopy. It was shown using polarography and turbidimetry that glycerol at low concentrations ​​(0.1–0.4 mM) increased the permeability of the inner membrane for NADH and succinate, while at high concentrations it severely damaged the membranes. Glycerol at low concentrations increased oxygen consumption by intact mitochondria in an isotonic medium with NADH or succinate, while at high concentrations it inhibited oxygen consumption. In a hypotonic medium, glycerol instantly inhibited NADH dehydrogenase, while it did not inhibit succinate dehydrogenase. The data we obtained allowed us to conclude that glycerol can be transported into mitochondria not only in the form of glycerophosphate, but directly by itself (passively along the concentration gradient). It was hypothesized that glycerol interacts with lipids and proteins and forms channels in the inner membrane for the its permeation and that of the substrates.