In Vitro Maturation and Fertilization of Follicular Oocytes Recovered from Pregnant Rabbits and the Maintenance of Pregnancy Following Ovarian Follicular Aspiration

妊娠家兎の卵胞(≧1.0mm)から卵胞卵を採取し、修正BO液で12時間培養した後、射出精子による体外受精を試みた所、成熱率、受精率、分割率、はそれぞれ93.1%(255/274)、39.2%(100/255)、28.2%(72/255)であった。合計41個の2-4細胞期の卵子を偽妊娠家兎4羽に移植した所、1羽に1個の着床部位が認められたが産仔は得られなかった。片側卵巣より卵胞を全て穿刺吸引した場合、妊娠13日目の家兎で胎児が部分吸収され、また妊娠19日目の家兎では胎児の部分吸収及び死産が認められたが、妊娠20日目から29日目に卵胞を穿刺吸引した家兎では正常な妊娠を維持した。妊娠19日目から29日目にかけて両側卵巣の卵胞を全て穿刺吸引した場合、妊娠19日目の家兎1羽を除く全ての家兎が正常な妊娠経過を示した。妊娠11日目から妊娠15日目に片側卵巣、また妊娠20日目から妊娠25日目の両側卵巣の卵胞を穿刺吸引し、その日から3日間連続して4mg/dayのProgesteroneを投与した所、全ての家兎が正常な妊娠を維持した。以上の結果より、妊娠期における卵胞卵の有効利用の可能性が示唆された。

In vitro maturation and fertilization of follicular oocytes recovered by puncture of large ovarian follicles (≧1.0 mm in diameter) from rabbits at 13 to 29 days post coitum (p. c.) were examined. Maturation and fertilization rates of the oocytes were 93.1% and 39.2%, respectively. Transfer of forty-one fertilized oocytes (2-4 cell stages) into oviducts of recipient does subjected to injection of hCG 24 hr before receiving the cleaved oocytes resulted in only one conceptus, which was missed in the latter stage of the pregnancy. Though the pregnant does from which oocytes were collected from the unilateral ovaries at 13 and 19 days p. c. showed partial stillbirth (13.3%) and resorption of fetuses (26.7%), dosage (4 mg/day) of progesterone (for 3 successive days after collection of oocytes) to unilaterally treated does at 11 to 15 days p. c. rescued their pregnancies. When all follicles on bilateral ovaries were aspirated at 20 to 29 days p. c., all pregnant does attained normal gestation.