title: Effects of hypothermic liquid storage and cryopreservation on basal and induced plasma membrane phospholipid disorder and acrosome exocytosis in boar spermatozoa.
abstract: Flow cytometry was utilised to determine whether short-term (Day 1) or long-term hypothermic liquid storage (Day 5), or cryopreservation of boar spermatozoa (1) caused changes in plasma membrane phospholipid disorder (MPLD) and acrosome exocytosis (AE), indicative of an advanced stage of capacitation or acrosome status, and (2) facilitated or inhibited the induction of capacitation and the acrosome reaction. Merocyanine with Yo-Pro-1 and peanut agglutinin-fluorescein isothiocyanate with propidium iodide were used to identify MPLD and AE, respectively, in viable spermatozoa. The incidence of basal sperm MPLD and AE in fresh semen was very low (1.1 and 2.2%, respectively) and was increased (P < 0.05) only a small amount in Day 5 and cryopreserved semen (3-8%). Compared to no bicarbonate, incubation with bicarbonate increased MPLD, but the response was greatest (P < 0.05) in fresh sperm (52.3%) compared with Day 1 (36.6%), Day 5 (13.9%) and cryopreserved sperm (13.6%). Incubation with calcium ionophore A23187 increased AE in spermatozoa, but the response was less (P < 0.05) for fresh (34%) and cryopreserved (27%) semen than for Day 1 (45%) and Day 5 (57%) semen. In summary, hypothermic liquid storage and cryopreservation of boar spermatozoa did not advance capacitation or acrosome status in viable spermatozoa, but did alter their responses to induction of capacitation and the acrosome reaction.
authors.affiliation: Biotechnology and Germplasm Laboratory, Agricultural Research Service, US Department of Agriculture, Beltsville, MD 20705, USA. dave@anri.barc.usda.gov
authors.forename: H D
authors.initials: HD
authors.lastname: Guthrie
authors.forename: G R
authors.initials: GR
authors.lastname: Welch
mesh_terms: D000177:Acrosome / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D001639:Bicarbonates / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D015925:Cryopreservation / Q000379:methods*; D004530:Egg Yolk / Q000378:metabolism; D005089:Exocytosis / Q000187:drug effects; D005434:Flow Cytometry / Q000379:methods; D016650:Fluorescein-5-isothiocyanate / Q000032:analysis / Q000378:metabolism; D005456:Fluorescent Dyes / Q000032:analysis / Q000378:metabolism; D007476:Ionophores / Q000494:pharmacology; D008297:Male; D008563:Membrane Lipids / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*; D012662:Semen Preservation / Q000379:methods*; D013075:Sperm Capacitation / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology*; D013552:Swine
chemical_list: D001639:Bicarbonates; D005456:Fluorescent Dyes; D007476:Ionophores; D008563:Membrane Lipids; D010743:Phospholipids; D000001:Calcimycin; D016650:Fluorescein-5-isothiocyanate