title: Chlortetracycline fluorescence patterns and in vitro fertilisation of frozen-thawed boar spermatozoa incubated under various bicarbonate concentrations.
abstract: Porcine oocyte-cumulus complexes were cultured in bovine serum albumin (BSA)-free North Carolina State University (NCSU) 23 medium containing porcine follicular fluid (10%), cysteine (0.1 mg/ml) and hormonal supplements (eCG and hCG: 10 IU/ml each) for 22h. They were then cultured in the same medium but without hormonal supplements for an additional 22 h. After culture, cumulus cells were removed and oocytes were co-incubated with frozen-thawed ejaculated boar spermatozoa in tissue culture medium (TCM) 199 containing caffeine (5 mM), fetal calf serum (FCS; 10%) and varying concentrations (26-56 mM) of NaHCO3 for 9 h (experiment 1). In experiment 2, chlortetracycline (CTC) was used to assess the functional state of spermatozoa incubated under different NaHCO3 concentrations. Experiment 3 examined the effect of FCS (1% and 10%) and NaHCO3 (26 and 46 mM) on fertilisation parameters. Compared with 26 mM, penetration rate was significantly higher (p < 0.05) at 36-56 mM NaHCO3. Polyspermy showed a similar pattern although no difference was observed between 26 and 36 mM. At 46 mM NaHCO3, the mean number of spermatozoa (MNS) penetrated per oocyte increased significantly (p < 0.05). A significantly higher proportion of spermatozoa were capacitated and acrosome reacted at 46 and 56 mM NaHCO3, respectively. The fertilisation medium containing 46 mM NaHCO3 and 1% FCS showed a higher penetration rate (84%) with a relatively low incidence of polyspermy (39%). The results indicate that NaHCO3 stimulates capacitation and/or the acrosome reaction of boar spermatozoa in a dose-dependent manner and thus affects fertilisation parameters.
authors.affiliation: Department of Animal Sciences, University of Missouri-Columbia, 65211, USA.
authors.forename: L R
authors.initials: LR
authors.lastname: Abeydeera
authors.forename: H
authors.initials: H
authors.lastname: Funahashi
authors.forename: N H
authors.initials: NH
authors.lastname: Kim
authors.forename: B N
authors.initials: BN
authors.lastname: Day
mesh_terms: D000818:Animals; D002751:Chlortetracycline; D005260:Female; D005307:Fertilization in Vitro / Q000187:drug effects*; D005312:Fetal Blood / Q000502:physiology; D005456:Fluorescent Dyes; D008297:Male; D008856:Microscopy, Fluorescence; D017693:Sodium Bicarbonate / Q000494:pharmacology*; D013075:Sperm Capacitation / Q000187:drug effects; D013084:Sperm-Ovum Interactions / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects* / Q000502:physiology; D013552:Swine
chemical_list: D005456:Fluorescent Dyes; D017693:Sodium Bicarbonate; D002751:Chlortetracycline