Subzero water transport characteristics and optimal rates of freezing rhesus monkey (Macaca mulatta) ovarian tissue

• Published in: Molecular reproduction and development Vol. 73; no. 12; pp. 1600 - 1611
• Main Authors: Li, G., Thirumala, S., Leibo, S.P., Devireddy, R.V.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.12.2006; Wiley-Liss
• Subjects: activation energy; Animals; Biological and medical sciences; calorimetry; Cell Membrane Permeability; Cell Size; cryopeservation; Cryopreservation - methods; Cryoprotective Agents - adverse effects; Cryoprotective Agents - analysis; Female; Ice - adverse effects; Macaca mulatta; Medical sciences; membrane permeability; Models, Theoretical; optimal cooling rate; ovarian tissue; Ovary - anatomy & histology; Specimen Handling - methods; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Technology. Biomaterials. Equipments; Temperature; Water - adverse effects; Water; optimal cooling rate; calorimetry; Cooling rate; membrane permeability; Monkey; Macaca mulatta; Permeability; Ovary; Vertebrata; Mammalia; Cryopreservation; Female genital system; Adult animal; Primates; Simioidea; activation energy; Cryoprotective agent; cryopeservation; ovarian tissue; Transport
• ISSN: 1040-452X; 1098-2795
• DOI: 10.1002/mrd.20541

The purpose of the present study was to examine the effect of two different suprazero (room temperature +25°C to +4°C) cooling conditions on the measured water transport response of primate (Macaca mulatta) ovarian tissue in the presence and absence of cryoprotective agents (CPAs). Freshly collected Macaca mulatta (rhesus monkey) ovarian tissue sections were cooled at either 0.5°C/min or 40°C/min from 25 to 4°C. A shape independent differential scanning calorimeter (DSC) technique was then used to measure the volumetric shrinkage during freezing of ovarian tissue sections at a freezing rate of 5°C/min in the presence and absence of three different CPAs (0.85 M glycerol, 0.85 M dimethylsulfoxide, and 0.85 M ethylene glycol). Thus, water transport during freezing of primate ovarian tissue was obtained at eight different conditions (i.e., at four different freezing media with two different suprazero cooling conditions). The water transport response of ovarian tissue cooled rapidly from 25 to 4°C was significantly different (P < 0.01) than that of slow cooled tissue, in the freezing media without CPAs and with dimethylsulfoxide. However, the differences in the measured water transport response due to the imposed suprazero cooling conditions were reduced with the addition of glycerol and ethylene glycol (statistically different with P < 0.05). By fitting a model of water transport to the experimentally obtained volumetric shrinkage data the best‐fit membrane permeability parameters (Lpg and ELp) were determined. The best‐fit parameters of water transport in primate ovarian tissue sections ranged from: Lpg = 0.7 to 0.15 µm/min‐atm and ELp = 22.1 to 32.1 kcal/mol (the goodness of fit parameter, R2 > 0.96). These parameters suggest that the “optimal rates of cryopreservation” for ovarian tissue are significantly dependent upon suprazero cooling conditions and the choice of CPA. Mol. Reprod. Dev. 73: 1600–1611, 2006. © 2006 Wiley‐Liss, Inc.