The Effect of Cold Shock and Freeze-Thawing on Release of Phospholipids by Ram, Bull, and Boar Spermatozoa

Abstract

The effects of cold shock and freeze-thawing on the release of total phospholipids phosphorus and of specific phospholipids from ram, bull, and boar spermatozoa are examined. Species differences are apparent, both in the absolute amount of total phospholipids released and in the conditions required to effect a loss of individual phospholipids. The phosphoglycerides most affected by the temperature treatment are choline plasmalogen, phosphatidyl choline, and phosphat idyl ethanolamine. The loss of phospholipids is most specific in boar spermatozoa. Bull spermatozoa suffer a greater overall and more general breakdown of phospholipids, indicating disruption of the cell structure. This is in contrast to the more specific phospholipid losses from ram and boar spermatozoa, which may indicate a more localized region of damage and release of material, possibly acrosomal. The loss of phospholipid may be correlated with the species differences in the fertility of the frozen spermatozoa.