Enhanced Embryo Development of Rabbit Oocytes Fertilized in Vitro With Platelet Activating Factor (PAF)-Treated Spermatozoa

The purpose of this study was to determine the effects of PAF treatment of rabbit spermatozoa on in vitro fertilization and subsequent blastocyst formation. Rabbit spermatozoa were exposed to PAF (10-7 M ), lyso-PAF (10-7 M ), or HIS (385 mOsm/kg) for 15 min prior to insemination of ovulated oocytes. Fertilized oocytes were cultured to the hatched blastocyst stage

Treatment of Sperm With High-Ionic Strength Medium Increases Microsurgical Fertilization Rates of Rabbit Oocytes Fertilized by Subzonal Placement of Sperm

This study was conducted to investigate the requirement for sperm processing in microsurgical subzonal placement of sperm in rabbit oocytes. Fertilization rates with standard in vitro fertilization and microsurgical subzonal sperm placement were found to be similar (56 and 55%) when sperm treated with high-ionic strength Brackett\u27s defined inedium to initiate capacitation were used. Statistically significant reductions in fertilization rates for both standard in vitro fertilization and subzonal placement were noted when twice-washed spermatozoa were used. Initiation of capacitation of spermatozoa results in higher fertilization results even when the zona pellucida is bypassed during fertilization

Survival and Cell Acquisition Rates After Preimplantation Embryo Biopsy: Use of Two Mechanical Techniques and Two Mouse Strains

Two strains of mouse embryos at the four- and eight-cell stages had biopsy specimens obtained by means of two different mechanical techniques: aspiration and displacement. Embryos and biopsy specimen cells were evaluated for survival and development. Blastomere acquisition rates were significantly higher with the displacement biopsy technique; however, no difference in survival or developmental rates was found in blastomere biopsy specimens removed from either four-cell or eight-cell embryos. A maximum of one blastomere can be removed from a four-cell embryo, whereas three blastomeres can be taken at biopsy from an eight-cell mouse embryo without significantly affecting embryo development, although mouse strain differences were noted. Intact, viable, biopsied blastomeres will develop in vitro when cocultured with morphologically intact embryos. Births of live offspring after embryo biopsy are reported

Spontaneous Zona Reaction in the Mouse as a Limiting Factor for the Time in Which an Oocyte May Be Fertilized

This study evaluated the effect of ovum aging on the in vitro fertilizability of mouse ova. Over 1347 ova were evaluated. Serial trypsin digestion of in vitro and in vivo aged ova revealed an increase in zona digestion time (0.25% trypsin) beginning at 40 hr, which increased over a 40-hr period and resulted in the unfertilized zona becoming as hard as the fertilized embryo zona. In vitro fertilizability showed a rapid decrease as zona hardening occurred with loss of cortical granules as assessed by electron microscopy. These data suggest that the window of fertilizability is closed by a spontaneous zona reaction occurring at about 55 hr post-human chorionic gonadotropin with loss of cortical granules and zona hardening as manifested by increasing zona digestion time with 0.25% trypsin

Platelet Activating Factor Enhances in Vitro Fertilization of Rabbit Oocytes

Capacitation of spermatozoa is essential for fertilization. Rabbit spermatozoa are particularly difficult to capacitate in vitro and require treatment with high-ionic-strength Brackett\u27s defined medium. Spermatozoa treated with platelet activating factor had significantly higher fertilization rates when compared with nontreated (fresh, twice washed) spermatozoa (63% vs 34%). Fertilization rates of spermatozoa treated with platelet activating factor, although higher than those of high-ionic-strength capacitated spermatozoa, were not significantly different (63% vs 57%). Spermatozoa treated with lyso-platelet activating factor, the biologically inactive form of platelet activating factor, were noted to have fertilization rates similar to those of the untreated (noncapacitated) group. These data show that synthetic platelet activating factor treatment of uncapacitatedspermatozoa induces fertilization of rabbit oocytes in vitro in a manner similar to that for spermatozoa capacitated by high-ionic-strength media and significantly higher than that for untreated spermatozoa or after treatment with the biologically inactive form of platelet activating factor (lyso-platelet activating factor)

Effects of Platelet Activating Factor on Mouse Oocyte Fertilization in Vitro

Platelet activating factor is rapidly gaining acceptance as a potent mediator in many reproductive processes. This study presents data that indicate a direct role of platelet activating factor in fertilization. Platelet activating factor was shown to significantly increase (p \u3c 0.001) the fertilization rate of mouse oocytes in vitro. Furthermore, CV3988, an inhibitor of platelet activating factor, was noted to significantly decrease in vitro fertilization rates at 10-5 and 10-4 mol/L concentrations. kw]Platelet activating factor, in vitro fertilization fa]Presented in part at the Thirty-sixth Annual Meeting of the Society for Gynecologic Investigation, San Diego, California, March 15-18, 1989