Stallion Mare Foal
Cholesterol-Loaded-Cyclodextrins and Fertility Potential of Stallion Spermatozoa
B.E. Spizziri, M.H. Fox, J.E. Bruemmer, E.L. Squires and J.K. Graham
Animal Reproduction and Biotechnology Laboratory, Colorado State University, Fort Collins, CO
Irreversible damage occurs to spermatozoal membranes, during the phase transition, when spermatozoa are cooled from room temperature to 5°C. Some of this damage can be ameliorated by adding cholesterol to the membrane, thereby altering membrane lipid composition. Adding cholesterol-loaded cyclodextrins (CLCs) to stallion spermatozoa prior to freezing, increases cell cryosurvival. However, the fertilizing potential of CLC-treated stallion spermatozoa is unknown. To address this, experiments were conducted which evaluated the ability of CLC-treated stallion spermatozoa to capacitate, acrosome react, and bind to the zona pellucida in vitro, and to fertilize oocytes in vivo. When CLC-treated cryopreserved stallion spermatozoa were treated with various agents to induce capacitation and the acrosome reaction (AR), dilauroylphosphatidylcholine (PC-12) and lysophosphatidylcholine (LPC) induced the AR in control cells (62% and 55%, respectively) but not in CLC-treated cells (17% and 14%, respectively, P < 0.05). However, the calcium ionophore A23187 induced the AR in both control- and CLC-treated cells equally well (39%, P > 0.05). Control- and CLC-treated stallion spermatozoa bound to ZP of cattle oocytes equally well (0.44 ± 0.16 vs. 0.25 ± 0.09, respectively; P > 0.05). In addition, the fertility rates of mares inseminated with control- and CLC-treated sperm were similar (P > 0.05).
published in: Animal Reproduction Science 118:223-228, April 2010
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