Yuzi Sakuma

Pregnancy by Means of Tubal Insemination and Subsequent Spontaneous Pregnancy in Rabbits

The purpose of the study was to determine whether or not physical stimulation by tubal insemination had any unfavourable influences upon the tubal fimbria. Tubal insemination was carried out on 14 rabbits and subsequent pregnancy results were monitored. After a period of 69 − 123 days following tubal insemination, 10 of the rabbits were mated spontaneously and these rabbits were then monitored for pregnancy. Newborn were obtained, with normal gestation periods in six out of the 14 rabbits, following tubal insemination and all 10 of the rabbits that were mated spontaneously with males following tubal insemination subsequently delivered. It is concluded that physical stimulation by tubal insemination does not produce adhesive changes on the tubal fimbria.

Effects of anti-progesterone compound RU486 on ovulation in immature mice treated with PMSG/hCG

The effects of RU486, a competitive antagonist of progesterone, on ovulation were studied in PMSG/hCG-treated immature mice. PMSG/hCG was administered to 3-week-old female mice to induce ovulation. A dose of 0.5 mg of RU486 was administered 3 h before hCG injection, simultaneously with hCG injection, or 3, 4.5, 6, 7.5 or 9 h after hCG administration. The lowest number of ovulated eggs was observed in the group given RU486 6 h after hCG injection. Although the mean number of ovulated eggs was only 4.4 in this group, it was increased to 25.7 by supplementary administration of 2.0 mg of progesterone. It was demonstrated that RU486 had inhibitory effects on ovulation, and the inhibition could be prevented by supplementary administration of progesterone.

Relation between the number of sperms to be deposited and pregnancy rate in tubal insemination in rabbits.

SummaryPregnancy rate of tubal insemination with semen diluted to concentrations of ×100 to ×107 was studied in rabbits. The animals were laparotomized under general anesthesia, and 0.05 ml of diluted semen was injected with a glass capillary from the tubal fimbria into the oviduct. The semen was obtained from mature male rabbits by means of an artificial vagina and diluted to concentrations between ×100 and ×107. One hour after the insemination, ovulation was induced by administration of hCG. Six experimental groups were set up according to the semen concentrations. In the ×100, ×102, ×104, and ×107 groups, newborn rabbits were obtained. The best pregnancy rate was obtained with the ×102 groups, in which 105 level of sperms were deposited. The newborn rabbits were normal not only morphologically, functionally, but also in chromosomal examination. The results suggested that tubal insemination with a small number of sperms could be applied in sterility due to oligospermia in human.

Superovulation inducement by administration of LH-RH preparation in mice

Abstract We attempted to induce superovulation in mice by using luteinizing hormone-releasing hormone (LH-RH) to develop follicles. Mice were treated with 5 I.U. of hCG at 17:00 h (Day 0), and then subcutaneously injected with 0.025 μg of an LH-RH analogue one to five times from Day 0 to Day 1. After a second injection of hCG at 17:00 h on Day 2, the oviducts were recovered on Day 3 and the ampulla were examined for ovulated ova. The mean number of ova for animals in the control group ( N =17) was 13.1, while those for all the experimental groups receiving LH-RH ranged from 15.4 to 24.1. The greatest number of ova (24.1) was obtained from the group which had received LH-RH five times at 22:00 h on Day 0, and at 02:00 h, 06:00 h, 10:00 h and 14:00 h on Day 1.

Effects of an Oil Contrast Medium on Fertilization in the Oviduct in Rabbits

The influence of an oil contrast medium on fertilization in rabbit oviducts was investigated. The oil contrast medium (Lipiodol-UF) was injected into the catheterized oviducts of anaesthetized animals, and they were mated 1, 3, 5 or 7 days later. When mating took place 1 day after injection, none of the ova that were subsequently recovered were fertilized; the fertilization rates when mating occurred 3, 5 or 7 days after injection of the medium were 78.9, 90 and 100%. Fertilization within the oviduct was, thus, impaired by the injection of oil contrast medium, but appeared to be fully recovered 7 days later.

Follicular recruitment for superovulation induction in rabbits by FSH dissolved in glycerol or a water-soluble salve base

Abstract We attempted to reduce the number of follicle stimulating hormone (FSH) injections for superovulation in rabbits by using glycerol and a water-soluble salve base as solvents. Three different forms of FSH preparation were each injected into the animals from one to three times. In the group injected with FSH dissolved in saline, the number of ovulation points only varied from 19.2 to 28.6 with the number of injections. In the group where glycerol was used as the solvent, the number of ovulation points increased remarkably from 24.8 to 33.8 to 43.8 with one, two and three injections respectively. This figure did not differ significantly from the result (51.2) obtained using the conventional programme involving six injections of FSH dissolved in saline. The use of the water-soluble salve base as the FSH solvent did not improve the number of ovulation points, even when the agent was given more frequently.