X-Message-Number: 9958
Date: Wed, 1 Jul 1998 04:41:54 -0700 (PDT)
From: Doug Skrecky <>
Subject: more on ethylene glycol 

2 Citations:

<1>
Authors
  Bautista JA.  Takahashi Y.  Kanagawa H.
Institution
  Department of Veterinary, Clinical Sciences, Graduate School of Veterinary
  Medicine, Hokkaido University, Sapporo, Japan. jobau:vetmed.hokudai.ac.jp
Title
  In vitro viability of mouse zygotes vitrified in ethylene glycol.
Source
  Japanese Journal of Veterinary Research.  45(4):193-8, 1998 Feb.
Abstract
  A study was made to determine if mouse zygotes can be effectively vitrified
  in 7 M ethylene glycol in modified Dulbecco's phosphate buffered saline (PB1)
  and to find out if the development of vitrified-warmed zygotes in vitro can
  be improved by renewing the culture medium. The results showed that without
  medium change, vitrification reduced the development of zygotes to the
  expanded blastocyst stage (p < 0.01). With medium change, the development
  rate of vitrified-warmed zygotes exposed in 7 M ethylene glycol for 1 or 2
  min was similar to that of unvitrified zygotes. However, prolonged exposure
  (5 min) markedly reduced the development rates of vitrified-warmed zygotes to
  the expanded blastocyst stage (p < 0.05). When the zygotes were vitrified in
  7 M ethylene glycol and diluted at 18 degrees C to 22 degrees C, a slower
  efflux of ethylene glycol from the cell might have occurred, leading to a
  toxic effect of ethylene glycol in culture. The development rates of
  vitrified embryos cultured with medium change at 24 hr did not significantly
  differ from the untreated control (89.0% vs 96.5%). In conclusion, this study
  showed that mouse zygotes can be vitrified in 7 M ethylene glycol in PB1 and
  that changing the culture medium can improve the in vitro development rates
  of vitrified-warmed zygotes to the expanded blastocyst stage.

<2>
Authors
  Bautista JA.  Kanagawa H.
Institution
  Department of Veterinary Clinical Sciences, Graduate School of Veterinary
  Medicine, Hokkaido University, Sapporo, Japan. jobau:vetmed.hokudai.ac.jp
Title
  Current status of vitrification of embryos and oocytes in domestic animals:
  ethylene glycol as an emerging cryoprotectant of choice. [Review] [41 refs]
Source
  Japanese Journal of Veterinary Research.  45(4):183-91, 1998 Feb.
Abstract
  The cryopreservation of mammalian embryos has become an integral part of
  methods to control animal reproduction. Numerous vitrification solutions have
  been formulated with ethylene glycol in combination with macromolecules,
  sugars and other cryoprotective agents.
  These indicate that a study of ethylene glycol as a cryoprotectant of choice
  in vitrification studies would be promising. To understand the cryobiology of
  ethylene glycol, several factors have to be studied. These are:
  cryoprotectant toxicity, osmotic stress and temperature at exposure.
  Understanding these factors could lead to the formulation of vitrification
  protocols that would lead to higher viability rates after cooling. First,
  ethylene glycol must be used as the sole cryoprotectant in a solution without
  macromolecules and sugars. Second, partial dehydration and permeation prior
  to cooling to subzero temperatures must be studied to achieve accurate
  exposure and a one-step dilution method. Third, the toxic effects of ethylene
  glycol must be overcome without sacrificing its vitrification properties by
  combining step-wise exposure at appropriate temperatures, low concentration
  and decreased volume. Fourth, the long-term effects of ethylene glycol on
  exposed or vitrified embryos must be determined. Lastly, the influence of
  culture on the viability of vitrified embryos must be studied to improve
  viability rates after warming. [References: 41]

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