X-Message-Number: 12190
Date: Sun, 25 Jul 1999 23:03:26 -0700 (PDT)
From: Doug Skrecky <>
Subject: effects of cryoprotectants on ovaries

Authors
  Candy CJ.  Wood MJ.  Whittingham DG.
Institution
  Department of Anatomy and Developmental Biology, St George's Hospital Medical
  School, London, UK.
Title
  Effect of cryoprotectants on the survival
  of follicles in frozen mouse ovaries.
Source
  Journal of Reproduction & Fertility.  110(1):11-9, 1997 May.
Abstract
  Ovaries from 10-day-old mice were exposed to 1.5 mol l-1 dimethylsulfoxide,
  1,2-propanediol, ethanediol or glycerol for 5-60 min at room temperature
  before freezing. Follicles in fresh and frozen ovaries were counted and
  scored as normal or damaged in stained serial sections. More primordial
  follicles survived in ovaries frozen in dimethylsulfoxide, 1,2-propanediol
  and ethanediol (81-94%) than in those frozen in glycerol (4-28%). Prolonged
  exposure to ethanediol (60 min) before cooling decreased the survival rate,
  while increasing the exposure to glycerol (> or = 12 min) increased the
  survival rate. Fewer than 49% of primary follicles survived freezing. After
  transfer underneath the kidney capsules of ovariectomized immunodeficient
  recipients, there was no difference in the establishment of grafts of fresh
  (92%) and frozen (90%) ovaries, the number of recipients showing vaginal
  cornification (fresh, 91%, frozen 96%) or the latency of cornification (11
  days). Fifteen days after transplantation, similar numbers of follicles
  remained in grafts of fresh ovaries, in ovaries frozen in dimethylsulfoxide
  and 1,2-propanediol, and in ovaries frozen after exposure to ethanediol for
  5-30 min. Overall, the total number of follicles remaining in grafts of
  ovaries frozen in dimethylsulfoxide and 1,2-propanediol represented 42-46% of
  follicles present in ungrafted ovaries. This was not significantly different
  from grafts of fresh ovaries (63%). Dimethylsulfoxide and 1,2-propanediol are
  the most effective cryoprotectants for
  10-day-old mouse ovaries. The majority of follicles are lost during graft
  establishment.

  Addition note by poster:

    The relatively poor results with glycerol could attributed to its
  relatively slow membrane permeability. This is a chronic problem for
  glycerol in the cryobiology literature, particularly with tissue blocks.
  
  Question:

    I don't understand why glycerol came to be the cryprotectant of choice
  for cryonics companies. I presume there must be some reason. Any replies
  on this?

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=12190