title: In-vitro penetration of pig oocytes matured in culture by frozen-thawed ejaculated spermatozoa.
abstract: Pig oocytes matured in culture were inseminated with frozen-thawed ejaculated spermatozoa without preincubation in modified tissue culture medium (TCM) 199. High penetration rates (85-89%) and increased incidence of polyspermy were obtained at 25-100 x 10(6) spermatozoa/ml. Wide variation in penetration rates (16-89%) was observed in oocytes inseminated in medium containing 5mM caffeine and at 25-50 x 10(6) spermatozoa/ml obtained from 6 boars, regardless of sperm motility. At 25-50 x 10(6) spermatozoa/ml, penetration rates of oocytes were dependent upon the concentration of caffeine in the medium: there was no penetration without caffeine, but penetration was highest (89%) with 5mM caffeine. None of the oocytes was penetrated in the medium supplemented with heparin at 5-40 micrograms/ml. When heparin was included in the medium with 5mM caffeine, it inhibited the efficacy of caffeine to promote sperm penetration of oocytes.
authors.affiliation: Division of Animal Science, Faculty of Agriculture, Okayama University, Japan.
authors.forename: W H
authors.initials: WH
authors.lastname: Wang
authors.forename: K
authors.initials: K
authors.lastname: Niwa
authors.forename: K
authors.initials: K
authors.lastname: Okuda
mesh_terms: D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002478:Cells, Cultured; D015925:Cryopreservation; D003470:Culture Media; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006493:Heparin / Q000494:pharmacology; D008297:Male; D009865:Oocytes / Q000166:cytology / Q000502:physiology; D012662:Semen Preservation; D013084:Sperm-Ovum Interactions / Q000187:drug effects; D013552:Swine / Q000502:physiology*
chemical_list: D003470:Culture Media; D002110:Caffeine; D006493:Heparin