The effect of chlorhexidine on some biochemical parameters of rat liver mitochondria.

Abstract

Abstract: Chlorhexidine (CHX) binds to isolated rat liver mitochondria with a saturation of binding at 900 nmol per mg protein. The binding is completed within 20 sec. and the binding does not render the mitochondria capable of sedimentation at 600 X g. A slight solubilization of mitochondrial proteins is obtained with 100 μM CHX, whereas higher concentrations of CHX (250 μM) result in an increase in the amount of protein sedimenting at 15,000 X g. Low concentrations of CHX (25 μM) have an uncouplinglike effect on the mitochondrial electron transport system. Inhibition of respiration is observed with 100 μM CHX. The activity of ATP‐ase is slightly stimulated with 15 μM CHX and inhibited 50% with 100 μM CHX. Membrane‐bound mitochondrial enzymes, e. g. succinate: cytochrome c reductase, proline oxidase and kynurenine hydroxylase are inhibited by CHX at 70 μM, 200 μM and 1 mM CHX respectively. Malate dehydrogenase (a mitochondrial matrix enzyme) is solubilized by CHX. At 25 μM CHX 87% of the activity is liberated from the mitochondrial matrix. The soluble enzyme is not inhibited by higher concentrations of CHX. The results are tentatively explained as being due to effects of binding of CHX to the mitochondrial membranes. Chlorhexidine is considered to be an amphipathic substance being capable of penetrating the non‐polar regions of phospholipid bilayers and at the same time being able to bind as a bication to phosphate groups in the phospholipids.