Egg recovery from the vagina of the rabbit treated with prostaglandin F2.ALPHA..
The egg recovery from the vagina was conducted 1 to 48 hours after administration of 2 or 5 mg/kg of body weight of prostaglandin F2α(PGF2α) in rabbits. The majority of eggs were recovered within 24 hours after treatment, especially more than 30% of the eggs were recovered by 2 hours after treatment, when a single administration of PGF2α was made 20 to 28 hours after mating. A high recovery rate (82.7±5.3%) was obtained by a subcutaneous injection of 5 mg/kg of PGF2α 22 hours after mating. The earliest eggs were recovered from the vagina at the first vaginal washing 1 hour after treatment.Multiple administrations of 2 or 5 mg/kg of PGF2α 72 to 114 hours after mating were applied to recover the blastocysts. However, only a scant number of eggs were recovered following the PGF2α administrations. Only 28.1±16.4% of the eggs were recovered from the vagina following the injections of 5 mg/kg of PGF2α at 96, 99 and 102 hours after mating. High implantation rates were demonstrated in spite of the multiple injections of PGF2α except in one group in which 5 mg/kg of PGF2α were applied at 108, 111 and 114 hours after mating. This fact indicates that the treatments with PGF2α on and after 3 days after mating have a lesser effect on the intrauterine egg transport than the early treatments 20 to 28 hours after mating.