title: A comparative study of the effects of glycerol and hydroxyethyl starch in canine red blood cell cryopreservation.
abstract: Hydroxyethyl starch (HES) is a nonpenetrating extracellular cryoprotectant. In contrast to glycerol, it does not require labor-intensive removal from thawed red blood cells (RBCs) prior to transfusion. In this study, we compared glycerol and HES, and assessed HES as a substitute for glycerol in cryopreserved canine RBCs. The RBCs were preserved for 2 months in liquid nitrogen using a 20% (w/v) glycerol solution, and variable concentrations of HES solution. We evaluated the two cryoprotectants by the percentage of post-thaw hemolysis from the total free hemoglobin, saline stability, osmotic fragility, and by observing the erythrocyte morphology using a scanning electron microscope after thawing. The optimal concentration of HES was 12.5% (w/v) for the cryopreservation of canine RBCs. The thaw hemolysis, saline stability, and osmotic fragility index were 25.6 +/- 4.7%, 87.8 +/- 6.9%, and 0.445 +/- 0.024% NaCl respectively. These parameters resemble the results of RBCs frozen in a 20% (w/v) glycerol solution, which are 24.7 +/- 5.2%, 99.2 +/- 0.1%, and 0.485 +/- 0.023% NaCl respectively. From a morphological point of view, 12.5% (w/v) HES showed the best cryoprotection of RBCs compared to the other concentrations of HES. These results suggest that HES could be a possible substitute for glycerol for the cryopreservation of canine RBCs.
authors.affiliation: The United Graduate School of Veterinary Sciences, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan.
authors.forename: Heejaung
authors.initials: H
authors.lastname: Kim
authors.forename: Shuhei
authors.initials: S
authors.lastname: Tanaka
authors.forename: Satoshi
authors.initials: S
authors.lastname: Une
authors.forename: Munekazu
authors.initials: M
authors.lastname: Nakaichi
authors.forename: Sajio
authors.initials: S
authors.lastname: Sumida
authors.forename: Yasuho
authors.initials: Y
authors.lastname: Taura
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods*; D004285:Dogs / Q000097:blood*; D004912:Erythrocytes / Q000187:drug effects* / Q000648:ultrastructure; D005990:Glycerol / Q000494:pharmacology*; D006461:Hemolysis / Q000187:drug effects; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology*; D008855:Microscopy, Electron, Scanning; D009584:Nitrogen
chemical_list: D006895:Hydroxyethyl Starch Derivatives; D009584:Nitrogen; D005990:Glycerol