X-Message-Number: 9440
Date: Fri, 10 Apr 1998 13:00:17 -0700 (PDT)
From: Doug Skrecky <>
Subject: dmso vs ethylene glycol

  Korbutt GS.  Rayat GR.  Ezekowitz J.  Rajotte RV.
Institution
  Surgical-Medical Research Institute and Department of Surgery, University of
  Alberta, Edmonton, Canada.
Title
  Cryopreservation of rat pancreatic islets: effect of ethylene glycol on islet
  function and cellular composition.
Source
  Transplantation.  64(7):1065-70, 1997 Oct 15.
Abstract
  BACKGROUND: Inasmuch as cryopreservation can facilitate clinical islet
  transplantation by providing a means of storing supplemental islets in order
  to augment marginally adequate grafts, protocols are needed to allow for a
  minimal loss in viable beta cells. By replacing the cryoprotectant dimethyl
  sulfoxide (DMSO) with ethylene glycol (EG), a more
  simplified cryopreservation protocol was developed, which resulted in
  improved survival and function of rat pancreatic islets. METHODS: Nonfrozen
  islets, islets cryopreserved in DMSO, and EG-cryopreserved
  islets were compared for percent recovery, cellular composition, in vitro
  viability, and metabolic function after transplantation. RESULTS: After
  cryopreservation in DMSO or EG, islet yield was similar to
  that of nonfrozen controls; however, islets cryopreserved in
  DMSO exhibited lower cellular DNA, insulin, and glucagon
  content, as well as an impaired insulin secretory capacity in vitro than the
  nonfrozen controls. When compared with controls, islets cryopreserved in
  DMSO contained a higher proportion of beta cells but a lower
  number of glucagon-positive cells, whereas cryopreservation with EG resulted
  in similar DNA/hormone contents, in vitro viability, and cellular
  composition. Transplantation of islet grafts composed of comparable numbers
  of beta cells (2.1-2.3 million) corrected diabetes in 100% (6/6; nonfrozen
  controls), 92% (10/11; DMSO), and 100% (14/14; EG) of the
  recipients; however, those who received DMSO-treated islets
  took longer to achieve euglycemia and remained glucose-intolerant.
  CONCLUSIONS: These results demonstrate that EG allows for the successful
  cryopreservation of rat islet beta and a cells with the same yield and
  quality as nonfrozen islets. The observation that alpha-cell survival was
  better after cryopreservation with EG may explain the improved functional
  viability of these grafts. Further studies are needed to assess whether this
  protocol provides any advantage for cryopreserving large numbers of human
  islets.

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