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

The purpose of the present study was to examine the effect of two different suprazero (room temperature þ258 Ct oþ48C) 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 0.58C/min or 408C/min from 25 to 48C. 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 58C/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 48C was significantly different (P 0.96). These parameters suggest that the ''opti- mal rates of cryopreservation'' for ovarian tissue are significantly dependent upon suprazero cooling condi- tions and the choice of CPA. Mol. Reprod. Dev. 73: 1600-1611, 2006. 2006 Wiley-Liss, Inc.