Permeability of ovine primordial follicles to different cryoprotectants

Objective: 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). Design: Isolated primordial follicles were exposed to the cryoprotectant (CPA) solution and photographed to calculate their volume at different periods of exposure. Setting: Laboratorio Renzo Giuliani, University of Florence, Italy. Animal(S): Lambs, 30-40 clays old. Intervention(s): Isolation of primordial follicles and subsequent exposure to CPA. Main Outcome Measure(S): Follicular volume. Result(s): 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, Conclusion(s): Volume changes in isolated primordial follicles can fluctuate according to the CPA used and its concentration.