X-Message-Number: 9488 Date: Tue, 14 Apr 1998 21:07:02 -0700 (PDT) From: Doug Skrecky <> Subject: membrane effects of ethylene glycol Biology of Reproduction 55: 161-168 1996 "Changes in Membrane Integrity, Cytoskeletal Structure, and Developmental Potential of Murine Oocytes After Vitrification in Ethyelene Glycol" Abstract: A systematic approach was taken to access and optimize a protocol for intracellular vitrification by introducing high concentrations of the cryoprotectant agent (CPA) ethylene glycol (EG) into unfertilized murine oocytes. The effects of EG on membrane integrity, microfilament organization, and developmental potential were evaluated. During exposure to 0.5-2 M EG, oocytes showed maximum shrinkage to 55.5% of the isotonic volume within the first minute and reexpanded to their initial volume within 15 min. Transferral of oocytes to higher concentrations of EG (4-8 M EG) for 1-5 min after 15 min of equilibration at 2 M eg was tolerated well. Microfilament organization appeared normal after this equilibration period. During prolonged exposure (>5 min) to high concentrations of EG (>4M), membrane blebs were noticed on the surface of the cells, and microfilament distribution was disturbed. After treatment with 6 M EG and vitrification with 6M EG + 0.5 M sucrose, there were no significant differences in development to the two cell and blastocyst stages between CPA-treated, vitrified, and control oocytes. These results indicate that EG is an effective CPA for mouse oocyte vitrification protocols without any observed compromise in morphology and developmental functions. Additional quote from text of report: "EG experiments were also carried out in the presence of sucrose, a well-known membrane stabilizer, to minimize the deleterious effects of high EG concentrations on membrane integrity. When oocytes equilibrated in 2 M EG for 15 min were exposed to concentrations of EG between 4 and 8 M with the addition of 0.5 M sucrose, bleb formation was completely suppressed for all EG concentrations tested for 30 min." Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=9488