[in Japanese]

View full abstract

Effects of prostagrandin F_2α (PGF_2α) on estrous cycle and fertility were studied in Holstein cows and heifers. Five mg of PGF_α disolved in 1.0 ml saline was given into the uterine body (UB) in six cows and a heifer, and three cows were given 10 mg of PGF_2α. One cow was given 5 mg of PGF_2α in 1.0 ml saline into the uterine horn ipsilateral to the corpus luteum (UH), and one heifer was given in the vagina adjacent to the cervix (V). Each cow and heifer was similarly treated with PGF_2α on day 9 of the estrous cycle (day 1= day of estrus).
Visual signs of estrus were checked with attention and the ovarian activity was examined by daily rectal palpation. All cows and a heifer were bred at the first estrus following PGF_2α treatment.
1) The diameter of corpus luteum was 2.3±0.4 cm at infusion of PGF_2α in UB and they decreased to 1.5 ± 0.5, 1.2 ± 0.3 cm on 1 and 2 days after treatment, respectively.
2) The interval from treatment of PGF_2α to estrus and ovulation rate in UB, UH and V was 2.7 ± 1.0 days, 7/10; 2 days, 1/1 and 2 days, 0/1, respectively.
3) Four cows and one heifer (UB) and one cow (UH) were conceived at the first estrus after the treatment of PGF_2α.

View full abstract

In order to clarify the individuality, the seasonal variation and the differences between each male genital organ, and the change with freeze-thawed treatment in boar seminal plasma.
The physico-chemical study on the seminal protein using the gel filtration with Sephadex G-200 and the starch gel electrophoresis was carried out.
Results obtained were as follows;
1. The boar seminal plasma was separated with starch gel electrophoresis into sixteen to eighteen fractions of protenious components, and the individual differences was shown in the number of protein bands and the positions of its appearance.
There was no proof of seasonal variation nor effect of freeze-thawed treatment by this technique.
2. The individuality of porteins in the boar seminal plasma was recognized with the gel filtration in the peaks accompanied with the protein contents. The fraction A of the filtrate showed the higher level in autumn than in summer season.
3. A similarity between the proteins of the seminal plasma and of the seminal vescular secretion was observed with both techniqes in this experiment.
The proteins in the fluid of cauda epididymis and of prostate gland mainly consisted of peak B and C.
These results suggest that the protein of peak A is derived mostly from the seminal vesicle fluid.

View full abstract

Effectiveness of an intrauterine injection of prostaglandin F_2α (PGF_2α) on the estrous synchronization in the grazing cow and the fertility at the synchronized estrus were investi-gated.
A total of 52 cows (Holstein 49 and Japanese Black Cattle 3) were treated with 4 or 6 mg of PGF_2α during the luteal stage (early 1. s. 7, functional 1. s. 41 and late 1. s. 4) Each doseof PGF_2α dissolved in 0.75 ml of aq. distillata was injected singly into the middle portion of an ipsilateral uterine horn to the corpus luteum through the cervix using the metal catheter. Estrus occurred in 12 (23.1%), 28 (53.9%) and 5 (9.6%) cows on 2, 3 and 4 days after the treat-ment respectively, and the remaining 7 cows (13.4%) between 9 and 16 days. It was noticeable that 14 cows which were considered to be silent or dull estrus during the period prior to the treatment revealed distinct estrous signs except 2 cows which showed weak heat. Out of 45 cows which came into estrus during 24 days after the treatment, 37 cows were inseminated with the frozen semen at that time and conceived in 27 cows (73.0%). Two cows were not served due to the weak heat or discharge of unclean mucus and 6 cows due to owner's wish.
These results indicate that an intrauterine injection of PGF_2α is an excellent method for the technique of the estrous synchronization in the cow.

View full abstract

Histochemical demonstrations of acid and alkaline phosphatases, and lactate andsuccinate dehydrogenases were made on hamster eggs at the stages of free blastocyst (3 days & 7 hours after ovulation), orientation (4 days & 13 hours), invasion (4 days & 16 hours, 4 days & 19 hours) and egg-cylinder (5 days & 7 hours). Gomori's metal method and BURSTONE's azo dye method were used for the demonstration of phosphatases, NACHLAS, WALKER and SELIGMAN'S method for lactate dehydrogenase, and NACHLAS et al. method for succinate dehydrogenase.
Acid phosphatase activity was strong in the inner cell mass of a free blastocyst and weak in its trophoblast. In the inner cell mass it markedly decreased at the orientation stage to remain weak throughout the later stages, while that in a trophoblastic giant cell at the invasion stage became somewhat stronger than it used to be in the trophoblast. Alkaline phosphatase activity was strong both in the inner cell mass and the trophoblast of a free blastocyst. In the inner cell mass it came to decrease at the orientation stage, to be further weakened at the invasion stage, while in a trophoblast, it showed little fluctuation throughout the develop-ment of the egg. Lactate dehydrogenase activity was stronger in the trophoblast than in the inner cell mass at every stage of the development, and succinate dehydrogenase activity was always weak in both the inner cell mass and the trophoblast.

View full abstract

The method of HEAP for the determination of progesterone was modified by introducing thin layer chromatography (TLC) and improving some conditions for coloration.
TLC was applied to isolation and purification of progesterone and 20 β-hydroxyprogesterone. Satisfactory results were obtained by developing a sample twice with n-hexane: ethylacetate (5:2) and once with benzene: ethyleacetate (2:1).
The most intense and stable fluorescence was obtained when the color was developed with concentrate sulfuric acid: ethanol (3:2) at 60°C for 10 minutes. When determined by the spect-rofluorometer, the maximum wavelength of this fluorescence presented peaks at 468 nm for excitation and 525 nm for emission. Under the same conditions as these the minimum amount of detection of 20 β-hydroxy progesterone was 2.5 ng.
The blood level of progesterone was determined by the modified method during the estrous cycle in four Japanese beef cows. Its minimum value was 0.2-0.8 ng/ml during the estrous period, and its maximum value 2.6, 6.2 ng/ml during the luteal phase (8 to 20 days after ovul-ation).

View full abstract

The fluorescence mothod of ITTRICH was applied to the determination of free estrogens in the peripheral blood of two Japanese beef cows during the estrous cycle.
The patterns of blood levels of estrone and estradiol were almost the same in tendency in the two cows during the estrous cycle. Estradiol was generally higher in level than estrone. Estriol was not detected at all. In the two cows, total estrogen increased in the proestrous phase, presenting a sharp peak at a level of 35.3 and 99.8 ng/liter (estrone, 5.9 and 16.0 ng/liter; estradiol, 29.4 and 83.8 ng/liter), respectively, prior to ovulation, and decreased rapidly to a minimum level, or 3.8 and 5.3 ng/liter (estrone, 1.6 and 1.9 ng/liter; estradiol, 2.2 and 3.4 ng/liter) after ovulation. In the luteal phase (68 days after ovulation), it reached a peak again at a level of 10.1 and 27.0 ng/liter (estrone, 2.4 and 3.4 ng/liter; estradiol, 7.7 and 23.6 ng/liter). In short, two peaks appeared during one estrous cycle.

View full abstract