During the several steps involved in the cryopreservation process, cells undergo changes in volume as water and solute enter and leave the cells. This osmotic response can be potentially lethal to the cells if it causes cells to swell or shrink beyond their osmotic tolerance limits . These limits can be determined by experimentally exposing cells to isosmotic and anisosmotic conditions; however, these experiments have not been performed using boar spermatozoa. Once these parameters have been identified, methods for CPA addition and removal can be estimated that would minimize cell volume excursion.
In addition to determining the osmotic tolerance limits for boar spermatozoa, optimizing methods for cryopreservation also requires defining the response of boar spermatozoa to permeating CPAs. By determining the rate at which CPAs and water permeate the boar sperm plasma membrane, and their temperature dependence, one can predict the amount of water loss and the potential for intracellular ice formation that cells will experience during cooling and warming. Thus the most optimal CPA and methods for its addition and removal can be estimated from this information. Buy Asthma Inhalers Online
The objectives of this study were 1) to determine the osmotic tolerance limits of boar spermatozoa; 2) to determine the permeability of boar spermatozoa to CPAs (glycerol, dimethyl sulfoxide [DMSO], and ethylene glycol [EG]) and to water, as well as their temperature dependence (Ea); 3) to predict an optimal CPA type and appropriate method for its addition and removal; and 4) to predict the amount of water loss experienced during cooling and warming and the associated probability of intracellular ice formation at various cooling and warming rates.