X-Message-Number: 12097
Date: Thu, 8 Jul 1999 21:25:18 -0700 (PDT)
From: Doug Skrecky <>
Subject: glycerol is slow to harm membranes

  Bakaltcheva IB.  Odeyale CO.  Spargo BJ.
  GeoCenters, Inc, Fort Washington, MD 20744, USA.
  Effects of alkanols, alkanediols and
  glycerol on red blood cell shape and hemolysis.
  Biochimica et Biophysica Acta.  1280(1):73-80, 1996 Apr 3.
  The physicochemical effects of a series of
  alkanols, alkanediols and glycerol on erythrocyte shape and
  hemolysis at 4 and 20 degrees C were examined. We calculated the dielectric
  constant of the incubation medium, Ds, and the dielectric constant of the
  erythrocyte membrane Dm in the presence of organic solutes. The ratio Ds/Dm =
  -38.48 at 20 degrees C defines the normal biconcave shape in a medium without
  hemolytic agents. A decrease in Ds/Dm favors externalization or
  internalization with consequent hemolysis. Alkanols and
  alkanediols convert biconcave erythrocytes into echinocytes, which is
  accompanied by an increase in the projected surface area. Glycerol converts
  biconcave erythrocytes into stomatocytes, which was accompanied by a marginal
  decrease in the projected surface area. Progressive externalization in
  alkanols and alkanediols or internalization in glycerol
  resulted in a decrease in the projected surface area and the formation of
  smooth spheres. The degree of shape change induced was related to the degree
  of hemolysis and the ratio Ds/Dm. A decrease in temperature reduced both the
  degree of shape change and hemolysis. Our results suggest that
  physicochemical toxicity may be a result of a temperature dependent
  hydrophobic interaction between the organic solutes and the membrane and is
  best interpreted by the ability of the solutes to change Ds and Dm. These
  results are discussed with respect to the physicochemical constants of the
  organic solutes.

  Additional note by poster:
    Glycerol was substantially less damaging to membranes than any of the
  other tested solutes in this experiment.

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