Permeability of ovine primordial follicles to different cryoprotectants

To determine the behavior of isolated primordial follicles that were exposed to different concentrations of dimethyl sulfoxide (DMSO), ethylene glycol (EG), propylene glycol (PROH), and glycerol (GLY). Isolated primordial follicles were exposed to the cryoprotectant (CPA) solution and photographed to calculate their volume at different periods of exposure. Laboratorio Renzo Giuliani, University of Florence, Italy. Lambs, 30–40 days old. Isolation of primordial follicles and subsequent exposure to CPA. Follicular volume. At 2 minutes of CPA exposure, all follicles appeared to be shrunken. At approximately 5 minutes, shrinkage ceased, and follicles started to swell, absorbing the CPA and water to maintain osmotic equilibrium. When DMSO was tested, follicular dehydration in all concentrations did not exceed 17%; with PROH and EG, it reached 33% and 27%, respectively. The highest degree of dehydration (48%) was seen with GLY. In almost all tested concentrations, follicular shrinkage occurred up to 5 minutes. Volume changes in isolated primordial follicles can fluctuate according to the CPA used and its concentration.