[in Japanese]

View full abstract

1. The breeding season in ewes usually begins in September, although a few ewes sometimes have the onset of oestrous cycle in late August. Ewes that do not come on oestrus until October are few. The onset of the breeding season in she-goats is a little later than that of ewes and not a few of the she-goats become to have the cycle during October.
2. As ovarian follicles grow even in anoestrus, there are various size of follicles in the ovaries, including medium or large follicles. But the growing follicles always degenerate at various stages of development and none of them can reach maturation and ovulation. Ovaries in anoestrus, therefore, contain no corpus luteum. Two kinds of growing follicles, normal and abnormal, are undistinguishable by the external appearance.
3. As the large follicles usually present in the ovaries, spontaneous oestrus and ovulation may be sonetimes induced by some environmental changes.
4. Twenty eight among thirty three she-goats came into oestrus and ovulated by the short day treatment. Owing to that the stimulation of light treatment is feeble and acts on the animals slowly, it takes long time to induce oestrus and ovulation. The effect of light treatment is influenced to some extent by other emvironmental conditions.
5. Stimulation using hormone is the method of inducing oestrus and ovulation rapidly. If the level of dosage is suitable normal ovulation can be induced in a few days. In the case of low unit of gonadotrophin (PMS 450 M. U. or HCG 500 I. U. or PMS+HCG I. U.) alone is used ovulation without oestrus is induced. When the gonadotraphin of above unit is used in conjunction with progesterone ovulation is acompanied by oestrus. In our experiment 135 mg. progesterone in total was injected for six days and 48 hours after the final injection gonadotrophin (PMS 450 M. U. or PMS+HCG 500-1000 I. U.) was injected. Nine she-goats came on oestrus out of ten treated animals and seven conceived.
6. In the case of high unit of PMS (900 M. U.) alone, ten she-goats came on oestrus out of eighteen treated and nine of them were served but only three conceived. When high unit of PMS is injected, excessive follicles are apt to grow simultaneously and some of them becme abnormal. Therefore, the normal function of the ovaries may be prevented. This is the reason why the conception rate is low.
7. The function of ovary is closely related with sexual cycle. There is no large follicle in the ovaries of ewes during few days after ovulation but we can find large follicle after 7 th day of the cycle. Ovaries of she-goats, however, often have large follicles soon after the ovulation but those follicles are abnormal in their tissue and are suggested to be degenerated later.
8. In order to lengthen the oestrous cycle ewes and she-goats that had normal cycles, were treated with various doses of progesterone. And the following treatment had the best results : The daily injection of 10 mg. progesterone was applied from 10-15 th day of the cycle for 7-11 days in ewes and from 15-16 th day of the cycle for 8-10 days in she-goats. Sixteen ewes and six she-goats were served when they came on oestrus few days after the final injection and twelve ewes and five she-goats conceived.
9. In order to shorten the oestrous cycle gonadotrophin (PMS+HCG 1000 I. U.) was injected during the luteal phase, 5-12 th day of the cycle, in ewes. Ovulation was induced from all of four treated ewes but none of them came on oestrus.

View full abstract

In general, the biological properties of ICSH and HCG are thought to be similar.However, some biological effects of HCG are distinct from that of ICSH. Differences in effects on the male reproductive organs were discussed in the preceding reports 6).
In the present paper, the potency of ICSH and HCG to induce ovulationwas compared. Adult female rats of the wistar strain showing the regular 4 dayestrous cycle were employed. Animals received the single subcutaneous injection on the afternoon of the day when the late diestrous smear stage wasshown. Twentyto twenty-two hours after the injection, they were sacrificed and the tubal ova were inspected under 10 time magnification. Hormones used were the same preparations as in the previous studies.6), 9) A given dose of the hormone was dissolved in 0.1 to 0.4 cc of saline on the day of the injection.
Summarized results of the induced ovulation by sheep ICSH and two preparations of HCG in rats areshown in Fig. 1. The dosage of gonadotrophins is expressed by the prostate unit, which is the convinient unit available to standardize the biological activity of any sort of gonadotrophic substances.6) To standardize the ovulation inducing activity of gonadotrophins, the authors define one rat ovulating unit as the amount ofhormone which will induce ovulation in 50 % of treated rats. One rat ovulating unit of preparations of sheep ICSH, purified and crude HCG is about 0.19, 11 and 25 Pr. U. respectively. Accordingly, it is clear that, in ICSH, the ovulation inducing potency is more active as compared with the effect stimulating androgensecretion, On the contrary, the ovulation inducing potency is very weak when compared with the androgen secreting activity in HCG. These results may give some suggestion in clinical apprication.
The dd strain mice is not so sensitive to sheep ICSH,

View full abstract

[in Japanese]

View full abstract

A simrle method for observing corpora lutea of the rat was described. This technique consists of compressing a fresh whole ovary between two glass slides and making it flat to a certain thickness (for adult females about 0. 2mm is suitable), and of observing it with a translucent light. By this procedure, all of corpora lutea present were displayed in one layer and able to be seen at one view. Comparative volumes of corpora lutea were detemined from the area occupied by each of them.
Using this technique, ovaries were observed on each day of the 4-day estrous cycle and or the 6 th day after copulation. Corpora lutea of the youngest and next youngest sets were easily distinguished by their characteristic color differences. In the cyclic rats, the most recently formed corpora lutea are lightgrey in early diestrus, become more opaque, brownish grey in late diestrus, followed by a marked increase in darkness between day of proestrus (brownish grey) and day of estrus (dark grey). By the next proestrus, they have shown uneven darkness and become indiscernible from older ones. Corpora latea of the impregnated animals are as light as those of cyclic ones at early diestrus. The volumes of corpora lutea of the cyclic and impregnated rats are as shown in Table 1 and Fig. 3.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

The effectiveness of HCG for treating ovarian disorders in cattle has been widely recognized. In our previous report, however, we demonstrated that the antihormone against HCG (Anti-HCG) was produced in considerable number of cattle which had been injected repeatedly with this hormone in order to treat ovarian follicle cysts and the majority of the Anti-HCG positive animals did not recover from this disease in spite of these treatments. Considering these facts, it appeared that the Anti-HCG positive sera might inhibit considerably gonadotrophic actions of HCG injected. In this report weperformed hormonal treatment of refractory ovarian follicle cysts in cattle by injecting HCG directly into the cysts. The purpose of the present studies was to ascertain whether this treatment was effective on cattle in which the Anti-HCG was produced. The animals used in the present studies were divided according to histories of HCG administrations into 2 groups, i. e. Group A including 10 animals and Group B including 12 animals.
Group A (shown in Table 1): The animals in this group had been received 1-3 injections of 10, 000-20, 000 MU or 5, 000-20, 000 IU of HCG intramuscularly within recent 4 months. They had not recovered from ovarian follicle cysts after these treatments and the serum Anti-HCG was determined to be positive in 6 animals (remaining 4 animals were not examined).
Group B (shown in Table 2): All animals in this group had never been received the HCG treatment.
The instrument used for injecting HCG solution directly into follicle cysts is shown in Figure 1. It was made up of a 10 cc. glass syringe and a vinyl tube (1.5 mm. in inside diameter and 55 cm. in length) attached to a needle (1.1 mm. in outside diameter and 4 cm. in length). The needle was introduced into the vagina with one hand, and thrust through the veginal wall. The cystic ovary was approched to the tip of the needle by the other hand per rectum. The needle was then stuck into the follicle cyst. After cystic fluid was drained off by sucking the syringe, 2-6 cc. of HCG solution was injected into the follicle cyst, The doses of HCG were decided according to histories of the HCG-treatments and conditions of the follicle cysts in the animals. The average dose injected into one sovery was 3, 540 MU (1, 000-6, 000 MU) in group A and 2, 100 MU (800-5, 000 MU) in group B.
The results obtained ware summarized as follows:
1. Group A: Four of 6 animals in which the serum Anti-HCG was determined to be positive, recovered respectively from ovarian follicle cysts by single treatment with HCG, and the other 2 animals recovered by double treatments. Three of 4 animals in which the Anti-HCG was not examined, recovered respectively by single treatment, and remaining 1 recovered by doble treatments.
Group B: Seven of 12 animals recovered respectively from ovarian follicle cysts by single treatment, and 2 of remaining 4 animals recovered by 2 or 3 treatments (one animal was sold after the 2nd-treament). Consequently, 9 of 12 animals (75.0%) recovered by this treatment.
2. In 19 animals in both groups which were recovered from ovarian cysts by this treament, days from the intrafollicular injection of HCG to the occurrence of normal estrus were 6-22 days (av. 14.0 days). It appeared that the periods from the HCG injection to recovery were relatively short in this treatment as compared with those in the customarily applied intramuscular or subcutaneous injections. Fifteen of these 19 cured animals were inseminated and 13 of them (86.7%) became pregnant.
3. From these results it was recognized that the injection of HCG solution directly into follicle cysts might be an available method of treating refractory ovarian cysts in cattle, especially in the Anti-HCG positive animals.

View full abstract

The effect of relaxin on in vitro spontaneous uterine contractions of the mouse was studied. Adult mice were ovariectomized at least 10 days before the experiment and treated with three daily injections of 0.5 μg. of estradiol benzoate, and used on the fourth day. Mice in estrus were also used. The estrus stage was determined by vaginal smear examination. The uteri were excised from these mice and suspended in a glass chamber of Locke's solution aerated with oxygen gass.
The spontaneous uterine motility under 1.5 gm. tension in the solution at 36.5°C was traced on a smoked drum of kymograph, using Magnus's method.
The uterine contractions of both groups of mice in estrus and mice estrogenized, spayed were inhibited completely by a small amount of relaxin (0.16 GPU/ml. of the solution in the chamber).
In comparison with a result of authors' previous report, the present one suggested that there seemed little defference in sensitivity to relaxin between the uteri of rats and mice.

View full abstract

[in Japanese]

View full abstract