Cholesterol-loaded-cyclodextrins and fertility potential of stallions spermatozoa.
Irreversible damage occurs to spermatozoal membranes, during the phase transition, when spermatozoa are cooled from room temperature to 5 degrees 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).
Spizziri
B E
BE
Animal Reproduction and Biotechnology Laboratory, Colorado State University, Campus Delivery 1680, Fort Collins, CO 80523, USA.
Fox
M H
MH
Bruemmer
J E
JE
Squires
E L
EL
Graham
J K
JK
D020101:Acrosome Reaction / Q000187:drug effects; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000032:analysis; D002462:Cell Membrane / Q000737:chemistry / Q000502:physiology; D002784:Cholesterol / Q000008:administration & dosage* / Q000032:analysis; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary; D003505:Cyclodextrins / Q000008:administration & dosage*; D005260:Female; D005298:Fertility; D006736:Horses / Q000502:physiology*; D007315:Insemination, Artificial / Q000662:veterinary; D007476:Ionophores / Q000494:pharmacology; D008297:Male; D011247:Pregnancy; D012662:Semen Preservation / Q000009:adverse effects / Q000379:methods / Q000662:veterinary; D013075:Sperm Capacitation / Q000187:drug effects; D013084:Sperm-Ovum Interactions / Q000187:drug effects; D013094:Spermatozoa / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure; D015044:Zona Pellucida / Q000378:metabolism
D003505:Cyclodextrins; D007476:Ionophores; D000001:Calcimycin; D002784:Cholesterol; D002118:Calcium